ASVAB Practice Exam 2

Answer: A. Carbohydrates break down into glucose, the fuel the body uses first for energy.

• ACorrect. Carbohydrates break down into glucose, the fuel body cells burn first for energy.
• BWrong. Proteins mainly build and repair tissues; the body burns them for energy only when carbohydrates and fats run short.
• CWrong. Vitamins help the body carry out chemical reactions, but they supply no calories (energy).
• DWrong. Minerals such as calcium and iron build bones and blood; they supply no calories.

Answer: D. White blood cells find and destroy bacteria, viruses, and other invaders.

• AWrong. Red blood cells carry oxygen from the lungs to the body; they do not fight germs.
• BWrong. Platelets are cell fragments that plug leaks and help blood clot.
• CWrong. Plasma is the liquid part of blood, not a cell; it carries nutrients, hormones, and wastes.
• DCorrect. White blood cells find and destroy bacteria, viruses, and other invaders; some also make antibodies.

Answer: A. The skeletal system is the framework of bones that supports and protects the body.

• ACorrect. The skeletal system is the framework of bones, with cartilage and ligaments, that supports and protects the body.
• BWrong. The muscular system is made of muscle tissue, which pulls on the bones to move them.
• CWrong. The nervous system is the brain, spinal cord, and nerves, which carry signals through the body.
• DWrong. The digestive system is the mouth, stomach, intestines, and related organs that break down food.

Answer: D. Igneous rock forms from cooled molten rock; granite and basalt are examples.

• AWrong. Sedimentary rock forms when layers of sediment, such as sand, mud, or shells, are pressed and cemented together.
• BWrong. Metamorphic rock forms when existing rock is changed by heat and pressure without fully melting.
• CWrong. Conglomerate is a sedimentary rock made of rounded pebbles cemented together, not cooled molten rock.
• DCorrect. Igneous rock forms when molten rock (magma underground, lava at the surface) cools and hardens; granite and basalt are examples.

Answer: A. Burning produces new substances (ash, carbon dioxide, water vapor), so it is a chemical change.

• ACorrect. Burning turns wood into new substances (ash, carbon dioxide, and water vapor) and gives off heat and light, the signs of a chemical change.
• BWrong. Melting only changes water from solid to liquid; it is still water, so this is a physical change.
• CWrong. Dissolved sugar is still sugar and can be recovered by evaporating the water, so dissolving is a physical change.
• DWrong. Cutting changes only the size and shape of the paper; each piece is still paper.

Answer: B. In conduction, heat passes particle to particle through direct contact, as along a solid metal spoon.

• AWrong. Convection carries heat by the movement of a liquid or gas, such as rising hot air; the solid spoon does not flow.
• BCorrect. In conduction heat passes particle to particle through direct contact, as along a solid metal spoon.
• CWrong. Radiation carries heat as electromagnetic waves, like sunlight or the warmth from a campfire, with no contact needed.
• DWrong. Insulation is the slowing of heat flow by a poor conductor, not a way heat travels.

Answer: A. The frog eats the grasshopper, which eats the grass, so the frog is a secondary consumer.

• ACorrect. The frog eats the grasshopper, a primary consumer, so the frog is a secondary consumer (the snake is third-level).
• BWrong. Grass is the producer in this chain; a frog cannot make its own food.
• CWrong. The grasshopper is the primary consumer because it eats the producer, the grass.
• DWrong. Decomposers break down dead matter; the frog eats living grasshoppers.

Answer: C. Every atom of an element has the same number of protons, and that number is the atomic number.

• AWrong. The number of neutrons can differ between atoms of the same element (isotopes), so it cannot identify the element.
• BWrong. Outer-shell (valence) electrons decide how an atom bonds; carbon, atomic number 6, has only 4 of them.
• CCorrect. Every atom of an element has the same number of protons, and that number is its atomic number; carbon always has 6.
• DWrong. Protons plus neutrons is the mass number, not the atomic number.

Answer: D. The rock’s volume is the rise in water level, 50 − 30 = 20 mL. Density = mass ÷ volume = 60 ÷ 20 = 3 g/mL.

• AWrong. 0.33 g/mL divides volume by mass (20 ÷ 60); density is mass divided by volume.
• BWrong. 1.2 g/mL divides by the final water level (60 ÷ 50) instead of the 20 mL rise.
• CWrong. 2 g/mL divides by the starting water level (60 ÷ 30) instead of the 20 mL rise.
• DCorrect. The rock’s volume is the rise in water level, 50 − 30 = 20 mL, so density = 60 ÷ 20 = 3 g/mL.

Answer: D. In the Sun’s core, extreme heat and pressure fuse hydrogen nuclei into helium, turning a little mass into a huge amount of energy.

• AWrong. Splitting heavy atoms such as uranium is nuclear fission, the process in nuclear power plants, not the Sun’s energy source.
• BWrong. Chemical burning releases far too little energy to keep the Sun shining for billions of years.
• CWrong. Shrinking under gravity could power the Sun for only tens of millions of years, far less than its age of about 4.6 billion years.
• DCorrect. In the Sun’s core, extreme heat and pressure fuse hydrogen nuclei into helium, turning a little mass into a huge amount of energy.

Answer: D. Newton’s second law: F = m × a = 12 kg × 2.5 m/s² = 30 N.

• AWrong. 4.8 N comes from dividing mass by acceleration (12 ÷ 2.5); force is mass times acceleration.
• BWrong. 9.5 N subtracts the acceleration from the mass (12 − 2.5), which has no physical meaning.
• CWrong. 14.5 N adds the mass and the acceleration (12 + 2.5); the two must be multiplied.
• DCorrect. Newton’s second law says F = m × a = 12 kg × 2.5 m/s² = 30 N.

Answer: B. Xylem is made of tube-like cells that carry water and dissolved minerals up from the roots.

• AWrong. Phloem carries the sugars made in the leaves to other parts of the plant.
• BCorrect. Xylem is made of tube-like cells that carry water and dissolved minerals up from the roots to the leaves.
• CWrong. Cambium is a thin layer of dividing cells that makes new xylem and phloem, so stems grow thicker.
• DWrong. The epidermis is the thin outer layer of cells that covers and protects leaves, stems, and roots.

Answer: C. A son gets his only X chromosome from his mother, who has one normal X and one color-blind X, so the chance is 1/2.

• AWrong. A son gets his X chromosome from his mother, not his father, so the father’s normal X cannot protect him; the risk is not zero.
• BWrong. 1/4 is the chance that any child (son or daughter) is a color-blind son, not the chance for a son.
• CCorrect. A son’s only X comes from his mother, who has one normal and one color-blind X, so the chance is 1/2.
• DWrong. A son would certainly be color-blind only if both of his mother’s X chromosomes carried the gene.

Answer: C. In anaphase the sister chromatids are pulled apart toward opposite poles of the cell.

• AWrong. In prophase the chromosomes condense and become visible, and the nuclear membrane breaks down.
• BWrong. In metaphase the chromosomes line up across the middle of the cell, still joined as pairs of chromatids.
• CCorrect. In anaphase the spindle fibers pull the sister chromatids apart toward opposite ends of the cell.
• DWrong. In telophase new nuclear membranes form around the two sets of chromosomes that have already separated.

Answer: B. Water has a high specific heat, so the ocean warms slowly in summer and releases stored heat slowly in winter, evening out the temperature of nearby air.

• AWrong. Open water absorbs most of the sunlight that strikes it when the Sun is high, so reflection does not explain the milder climate.
• BCorrect. Water has a high specific heat, so the ocean warms slowly in summer and gives back stored heat slowly in winter, evening out nearby air temperatures.
• CWrong. Heat reaching the seafloor from Earth’s interior is tiny compared with sunlight and does not control coastal climate.
• DWrong. Evaporation absorbs heat and cools the water; it is condensation that releases heat.

Answer: D. 6 cases × 24 cans in each = 144 cans.

• AWrong. 4 divides 24 by 6. Equal groups combine by multiplying.
• BWrong. 18 subtracts 6 from 24 instead of multiplying.
• CWrong. 30 adds 24 and 6 instead of multiplying.
• DCorrect. 6 cases × 24 cans in each = 144 cans.

Answer: A. 150 ÷ 6 = 25 feet.

• ACorrect. 150 ÷ 6 = 25 feet.
• BWrong. 30 feet divides by 5, the number of cuts. Making 6 pieces takes 5 cuts, but the rope is shared among 6 pieces.
• CWrong. 144 feet subtracts 6 from 150 instead of dividing.
• DWrong. 156 feet adds 6 to 150 instead of dividing.

Answer: C. $18 × 6 hours = $108 a day, and $108 × 5 days = $540 a week.

• AWrong. $90 is $18 × 5. It treats $18 as the pay for a whole day and ignores the 6 hours.
• BWrong. $108 is one day's pay. It still has to be multiplied by 5 days.
• CCorrect. $18 × 6 hours = $108 a day, and $108 × 5 days = $540 a week.
• DWrong. $720 is $18 × 40. It assumes a 40-hour week, but the cashier works only 6 × 5 = 30 hours.

Answer: D. 30 minutes is 1/2 hour, so the ride lasts 2 1/2 hours: 12 × 2 1/2 = 30 miles.

• AWrong. 4.8 divides 12 by 2 1/2. Distance is speed times time, so multiply.
• BWrong. 24 counts only the 2 full hours and leaves out the extra 30 minutes.
• CWrong. 27.6 treats 2 hours 30 minutes as 2.3 hours. 30 minutes is 0.5 hour, not 0.3 hour.
• DCorrect. 30 minutes is 1/2 hour, so the ride lasts 2 1/2 hours: 12 × 2 1/2 = 30 miles.

Answer: A. 28 × 15 = 420 seats. 420 − 347 = 73 empty seats.

• ACorrect. 28 × 15 = 420 seats. 420 − 347 = 73 empty seats.
• BWrong. 83 comes from a borrowing slip in 420 − 347: after borrowing, the tens digit 2 becomes 1, so the answer is 73.
• CWrong. 420 is the total number of seats. The 347 sold seats still have to be subtracted.
• DWrong. 767 adds the tickets sold to the seats instead of subtracting them.

Answer: B. 15% of $240 is 0.15 × 240 = $36. The sale price is $240 − $36 = $204.

• AWrong. $36 is the discount. It still has to be subtracted from $240.
• BCorrect. 15% of $240 is 0.15 × 240 = $36. The sale price is $240 − $36 = $204.
• CWrong. $225 takes off $15 instead of 15% of $240, which is $36.
• DWrong. $276 adds the $36 discount to the price instead of subtracting it.

Answer: A. Each person needs 2 1/2 ÷ 4 = 5/8 cup, and 10 × 5/8 = 6 1/4 cups.

• ACorrect. Each person needs 2 1/2 ÷ 4 = 5/8 cup, and 10 × 5/8 = 6 1/4 cups.
• BWrong. 8 1/2 cups adds 1 cup for each of the 6 extra people. Each person needs only 5/8 cup.
• CWrong. 10 cups multiplies 2 1/2 by 4 instead of dividing by 4 to find the flour for one person.
• DWrong. 25 cups treats 2 1/2 cups as the amount for one person, but it serves 4.

Answer: D. 40 × $15 = $600 regular pay and 6 × $22.50 = $135 overtime pay. $600 + $135 = $735.

• AWrong. $135 is only the overtime pay. The $600 regular pay must be added.
• BWrong. $600 is only the regular pay. The 6 overtime hours add $135.
• CWrong. $690 pays all 46 hours at $15. The 6 overtime hours pay $22.50 each.
• DCorrect. 40 × $15 = $600 regular pay and 6 × $22.50 = $135 overtime pay. $600 + $135 = $735.

Answer: D. A 6-inch tile is 1/2 foot by 1/2 foot, or 1/4 square foot. The floor is 10 × 12 = 120 square feet, so it takes 120 ÷ 1/4 = 480 tiles.

• AWrong. 20 divides 120 square feet by 6 without changing inches to feet.
• BWrong. 120 is the floor area in square feet, not the number of tiles.
• CWrong. 240 treats each tile as 1/2 square foot. A tile 1/2 foot on each side covers only 1/4 square foot.
• DCorrect. A 6-inch tile is 1/2 foot by 1/2 foot, or 1/4 square foot. The floor is 10 × 12 = 120 square feet, so it takes 120 ÷ 1/4 = 480 tiles.

Answer: A. Each hour the pumps fill 1/6 + 1/3 = 1/2 of the tank, so together they need 2 hours.

• ACorrect. Each hour the pumps fill 1/6 + 1/3 = 1/2 of the tank, so together they need 2 hours.
• BWrong. 4 1/2 hours averages the two times. Two pumps together must be faster than the faster pump alone.
• CWrong. 9 hours adds the times, as if one pump ran after the other.
• DWrong. 18 hours is 6 × 3, only the top of the formula (6 × 3) ÷ (6 + 3). Dividing by 9 gives 2 hours.

Answer: D. Each worker lays 360 ÷ (3 × 4) = 30 bricks an hour. 5 workers × 6 hours × 30 = 900 bricks.

• AWrong. 400 flips the time ratio (× 4/6). More hours means more bricks, so multiply by 6/4.
• BWrong. 540 adjusts for the 6 hours but not for the 5 workers.
• CWrong. 600 adjusts for the 5 workers but not for the 6 hours.
• DCorrect. Each worker lays 360 ÷ (3 × 4) = 30 bricks an hour. 5 workers × 6 hours × 30 = 900 bricks.

Answer: C. Rent is 1/4 of $1,200 = $300, leaving $900. Food is 1/3 of $900 = $300, leaving $600.

• AWrong. $300 is the amount spent on rent (and also on food), not the amount left.
• BWrong. $500 takes 1/3 of the whole $1,200 ($400) for food. Food is 1/3 of the $900 left after rent.
• CCorrect. Rent is 1/4 of $1,200 = $300, leaving $900. Food is 1/3 of $900 = $300, leaving $600.
• DWrong. $900 is what is left after rent only. Food still has to come out.

Answer: A. The final cost is 0.75 × 1.08 = 0.81 of the original price. $81 ÷ 0.81 = $100.

• ACorrect. The final cost is 0.75 × 1.08 = 0.81 of the original price. $81 ÷ 0.81 = $100.
• BWrong. $101.25 adds 25% of $81 back on. The 25% was taken from the original price, not from $81, and the tax is ignored.
• CWrong. $107.73 adds 25% and 8% of $81 back on. Percents of different amounts can't be combined this way.
• DWrong. $108.00 undoes the 25% discount ($81 ÷ 0.75) but not the 8% tax.

Answer: A. 4 inches is 1/3 foot. 18 × 12 × 1/3 = 72 cubic feet, and 72 ÷ 27 = 2 2/3 cubic yards.

• ACorrect. 4 inches is 1/3 foot. 18 × 12 × 1/3 = 72 cubic feet, and 72 ÷ 27 = 2 2/3 cubic yards.
• BWrong. 8 divides 72 cubic feet by 9, the square-foot-to-square-yard factor. A cubic yard is 27 cubic feet.
• CWrong. 32 multiplies by 4 as if the patio were 4 feet thick. The 4 inches must first become 1/3 foot.
• DWrong. 72 is the volume in cubic feet. It still has to be divided by 27 to get cubic yards.

Answer: C. The can holds 3 gallons of white and 2 of blue. For 4 to 1, white must be 4 × 2 = 8 gallons, so add 8 − 3 = 5 gallons.

• AWrong. 1 subtracts the ratio numbers (4 − 3). The ratios describe parts, not gallons.
• BWrong. 3 is the white paint already in the can, not the amount to add.
• CCorrect. The can holds 3 gallons of white and 2 of blue. For 4 to 1, white must be 4 × 2 = 8 gallons, so add 8 − 3 = 5 gallons.
• DWrong. 8 is the total white needed. The 3 gallons already in the can come off: 8 − 3 = 5.

Answer: C. To begin something is to start it.

• AWrong. To try is to make an attempt; you can try something without being at its start.
• BWrong. To wait is to hold off until something happens, not to set it going.
• CCorrect. Begin and start both mean to take the first step in doing something.
• DWrong. To finish is to bring something to an end, the opposite of begin.

Answer: B. To shout is to call out loudly, which is what yell means.

• AWrong. To sing is to make music with the voice; it can be soft or loud.
• BCorrect. To shout is to yell: to say something in a very loud voice.
• CWrong. To borrow is to take something you will give back later.
• DWrong. To whisper is to speak very softly, the opposite of shout.

Answer: A. A chore is a routine job or task, often a household one.

• ACorrect. A chore is a task, usually a routine one such as washing dishes.
• BWrong. A break is a short rest from work, the opposite of doing a chore.
• CWrong. A hobby is an activity done for fun in free time, unlike a chore.
• DWrong. A prize is a reward given to a winner.

Answer: A. Damage is harm done to something, such as broken windows after a storm.

• ACorrect. Damage is harm or injury done to property or people.
• BWrong. A delay is a wait or hold-up; a storm can cause delays, but that is not what damage means.
• CWrong. A benefit is something helpful or good, the opposite of damage.
• DWrong. Flooding is water overflowing onto land. It fits a storm, but damage means harm of any kind, not water.

Answer: D. Vague means not clear or exact, so a vague answer leaves the listener unsure.

• AWrong. Angry means upset and annoyed; an answer can be calm and still vague.
• BWrong. Brief means short. A short answer can be very clear, so brief is not the same as vague.
• CWrong. Direct means straight to the point, the opposite of vague.
• DCorrect. Vague means unclear: not stated in a definite way.

Answer: D. Gradual means happening slowly, a little at a time.

• AWrong. Sudden means happening all at once, the opposite of gradual.
• BWrong. Impressive means deserving admiration; it says nothing about how fast change happens.
• CWrong. Long-lasting means continuing for a long time; it describes how long something lasts, not how it builds up.
• DCorrect. Gradual means happening by small steps over time.

Answer: A. To purchase something is to buy it.

• ACorrect. Purchase means to buy: to get something by paying for it.
• BWrong. To owe is to have a debt, to need to pay money back.
• CWrong. To rent is to pay to use something for a time without owning it.
• DWrong. To sell is to give something up in exchange for money, the opposite of purchase.

Answer: D. A remedy is a treatment or cure for an illness or a problem.

• AWrong. A habit is something a person does regularly, often without thinking.
• BWrong. An illness is a sickness, the thing a remedy is meant to fix, so it is close to the opposite.
• CWrong. A symptom is a sign of illness, such as a cough. It is linked to sickness, but it is not a cure.
• DCorrect. A remedy is a treatment that cures or relieves an illness or problem.

Answer: C. Frugal means careful not to waste money, which is what thrifty means.

• AWrong. Poor means having little money. A frugal person may be rich or poor; frugal is about how money is spent.
• BWrong. Greedy means wanting more than one needs.
• CCorrect. Frugal and thrifty both mean using money and goods carefully.
• DWrong. Wasteful means using things carelessly, the opposite of frugal.

Answer: A. To alleviate is to make something, such as worry or pain, less severe.

• ACorrect. Alleviate means to ease: to make a worry or pain lighter.
• BWrong. To raise concerns is to bring them up or add to them, the opposite of alleviate.
• CWrong. To ignore is to pay no attention to something; ignoring concerns does not lessen them.
• DWrong. To explain is to make something clear. The mayor might explain the tax, but explain does not mean lessen.

Answer: D. To bolster something is to support it or make it stronger.

• AWrong. To shake someone's confidence is to weaken it, the opposite of bolster.
• BWrong. To express is to put into words. A speech can express confidence, but bolster means to build it up.
• CWrong. To measure is to find out how much of something there is.
• DCorrect. Bolster means to strengthen or support.

Answer: D. Reluctant means unwilling or hesitant to do something.

• AWrong. Eager means wanting very much to do something, the opposite of reluctant.
• BWrong. Unable means not able; a reluctant person can act but does not want to.
• CWrong. Allowed means permitted. Rules about sharing results fit the setting, but reluctant is about willingness.
• DCorrect. Reluctant means unwilling or hesitant.

Answer: B. Animosity is strong dislike or hostility toward someone.

• AWrong. Envy is wanting what someone else has. It is an unfriendly feeling, but it is not the same as hatred.
• BCorrect. Animosity is hatred or strong ill will.
• CWrong. Goodwill is a friendly, kind attitude, the opposite of animosity.
• DWrong. Curiosity is the wish to know or learn about something.

Answer: D. Ephemeral means lasting only a very short time.

• AWrong. Imaginary means existing only in the mind, not real.
• BWrong. Permanent means lasting forever, the opposite of ephemeral.
• CWrong. Unearthly means strange or not of this world. Ephemeral can sound airy, but it is about time, not strangeness.
• DCorrect. Ephemeral means short-lived, like a soap bubble.

Answer: C. An impetus is a driving force that makes something happen or move forward.

• AWrong. A careful plan is a thought-out method. A plan says how to act; an impetus is what pushes you to act.
• BWrong. Sudden anger is a quick burst of temper; impetus only looks like the word impetuous.
• CCorrect. Impetus means a driving force, the push that gets something going.
• DWrong. A main obstacle is the chief thing holding something back, the opposite of an impetus.

Answer: B. The sentences after "well suited" list features that help camels survive in the desert. Being well suited to a place means being adapted to it.

• AWrong. This plays on the clothing meaning of "suit." The passage is about body features that help camels survive, not about clothing.
• BCorrect. Every detail that follows (going days without water, protective eyelashes, wide feet) shows how the camel's body fits desert life, so "suited" means adapted.
• CWrong. The passage shows camels doing well in the desert, not being held back or restricted to it.
• DWrong. Nothing in the passage says camels are drawn to the desert. It describes how their bodies help them live there.

Answer: C. Every sentence supports one message: used batteries cause harm in the trash, so take them to a collection point. The key restates that message in new words.

• AWrong. The passage says some batteries "can" start truck fires. It does not say this happens often, and it is only one supporting detail.
• BWrong. This reverses the passage, which says the stores and town offices collect batteries for free.
• CCorrect. The passage explains the harm of trashing batteries and ends by telling readers to drop them off instead. That is the point of the whole passage.
• DWrong. This is true according to the passage, but it is a single supporting detail and does not sum up the message.

Answer: B. The first sentence says the north lot will be closed for repaving starting Monday. The key restates this as the work on that lot beginning.

• AWrong. The south lot is where employees are told to park. Only the north lot is being repaved.
• BCorrect. The notice says the north lot closes for repaving starting Monday, so the paving work begins then.
• CWrong. This reverses the notice. The shuttle is part of the plan for while the north lot is closed; nothing says it stops.
• DWrong. The Birch Road lot stays open as an overflow lot. It is the north lot that closes for about three weeks.

Answer: D. The passage sets two rules: be at least 18 and owe no fines. Only the 16-year-old breaks a rule.

• AWrong. This member is over 18 and has no unpaid fines, so both rules are met.
• BWrong. The rule is that a member must not owe fines. A fine that has been paid is no longer owed, so this member qualifies.
• CWrong. Members must be "at least 18," so an 18-year-old with no fines meets both rules.
• DCorrect. A member must be at least 18 years old. A 16-year-old fails that rule even with no fines.

Answer: A. The passage compares transport before and after the canal and ends with the benefits to farmers and trade. Its main point is that the canal made moving goods much cheaper.

• ACorrect. The passage contrasts slow, costly wagon travel with canal boats that cost a small fraction as much, and shows how trade grew as a result.
• BWrong. This reverses the passage. Wagon hauling is described as the slow, costly way goods moved before the canal.
• CWrong. Mules appear only as the animals that pulled canal boats. The passage never ranks them against other animals.
• DWrong. The passage says farmers could sell their crops in the East, not that they grew more of them.

Answer: B. The author states a common belief and then gives evidence against it. The purpose is to correct that belief.

• AWrong. The passage never discusses treatment. Arthritis comes up only as the supposed result of knuckle cracking.
• BCorrect. The passage opens with a common belief and then uses study results to show there is little evidence for it.
• CWrong. The studies are mentioned only as evidence. The passage gives no history of joint research.
• DWrong. The author does not urge anyone to stop and concludes the habit probably does not cause arthritis.

Answer: C. The sequence is register and read eligibility information, health interview and checks, collection, then rest. Reading the eligibility rules comes before the checks.

• AWrong. Resting with a snack is the last step, after the donation.
• BWrong. Blood is collected only after the donor passes the health check.
• CCorrect. Donors register and read eligibility information first; the health check with pulse and blood pressure comes "then."
• DWrong. The needle is used to collect blood, which happens after the health check.

Answer: D. The third sentence gives the shortcut: after six months of residence, a settler could pay $1.25 an acre instead of waiting five years.

• AWrong. Farming the land was one requirement of the five-year path, not a shortcut, and one season is not enough.
• BWrong. Selling land is never mentioned in the passage.
• CWrong. Being a head of household made a person eligible to file a claim. It did not shorten the time needed to own the land.
• DCorrect. The passage says a settler could buy the land after six months of living on it, at $1.25 an acre, instead of waiting five years.

Answer: C. The stages are snow buildup, rounded grains, firn, closing of the air spaces into dense ice, and then flow. Closing of the air spaces falls between firn and flow.

• AWrong. Flowing downhill is the final stage, after dense ice has formed.
• BWrong. The flakes become rounded grains before the snow is called firn, so this comes earlier.
• CCorrect. After firn forms, continued burial squeezes it until the air spaces between grains close off. Only later does thick ice begin to flow.
• DWrong. This is the starting condition for a glacier, well before firn forms.

Answer: A. The passage explains how resistance builds, how misuse speeds it up, and why careful use is urged. The key combines that cause and the call for care.

• ACorrect. The passage explains how drug use favors resistant bacteria, how misuse worsens the problem, and why agencies urge using antibiotics only when needed.
• BWrong. The passage does say this, but only as one example of misuse. It is not the main idea.
• CWrong. The passage says a few bacteria already carry differences that let them survive; the drug does not create them by damaging genes.
• DWrong. This contradicts the passage, which says new antibiotics are slow and costly to develop.

Answer: B. Area of a triangle = ½ × base × height = ½ × 10 × 6 = 30 sq in.

• AWrong. 16 adds the base and the height instead of multiplying them.
• BCorrect. ½ × 10 × 6 = 30 sq in.
• CWrong. 32 is 2 × (10 + 6), a perimeter-style sum, not an area.
• DWrong. 60 is base × height without the ½; that is the area of a 10-by-6 rectangle.

Answer: C. Angles that form a straight line add to 180°, so x = 180 − 65 = 115.

• AWrong. 25 subtracts 65 from 90, as if the angles made a right angle.
• BWrong. 65 assumes the two angles are equal; they only add to 180°.
• CCorrect. Angles on a straight line add to 180°: x = 180 − 65 = 115.
• DWrong. 295 subtracts 65 from 360, the total around a point, not along a line.

Answer: A. Combine like terms: 3x − x = 2x and 5 + 2 = 7, so the result is 2x + 7.

• ACorrect. 3x − x = 2x and 5 + 2 = 7, giving 2x + 7.
• BWrong. 2x + 3 subtracts the 2 from the 5; the +2 is added.
• CWrong. 3x + 7 drops the −x term.
• DWrong. 4x + 7 adds x to 3x instead of subtracting it.

Answer: C. 36 = 12 × 3 and 48 = 12 × 4, and 3 and 4 share no factor except 1, so the GCF is 12.

• AWrong. 4 divides both numbers, but it is not the greatest common factor.
• BWrong. 6 divides both numbers, but it is not the greatest common factor.
• CCorrect. 36 = 12 × 3 and 48 = 12 × 4, with 3 and 4 sharing nothing more, so the GCF is 12.
• DWrong. 144 is the least common multiple of 36 and 48, not a factor.

Answer: A. Subtract 5: 2x < 12. Divide by 2: x < 6. Dividing by a positive number keeps the sign.

• ACorrect. Subtract 5 (2x < 12), then divide by 2: x < 6.
• BWrong. x > 6 flips the sign, which is done only when multiplying or dividing by a negative number.
• CWrong. x < 11 adds 5 to 17 (2x < 22) instead of subtracting it.
• DWrong. x < 12 stops at 2x < 12 and never divides by 2.

Answer: B. The side of length 13 is the hypotenuse, so x² = 13² − 5² = 169 − 25 = 144 and x = 12.

• AWrong. 8 subtracts the side lengths (13 − 5) instead of their squares.
• BCorrect. x² + 5² = 13², so x² = 169 − 25 = 144 and x = 12.
• CWrong. √194 adds the squares (169 + 25), treating x as the hypotenuse; x is a leg.
• DWrong. 18 adds the two side lengths (13 + 5).

Answer: D. (x + 3)² = (x + 3)(x + 3) = x² + 3x + 3x + 9 = x² + 6x + 9.

• AWrong. x² + 9 squares each term and leaves out the middle term 6x.
• BWrong. x² + 3x + 9 counts the 3x product only once; it appears twice.
• CWrong. x² + 6x + 6 doubles the 3 for the last term instead of squaring it.
• DCorrect. (x + 3)(x + 3) = x² + 3x + 3x + 9 = x² + 6x + 9.

Answer: B. 2⅓ = 7/3, and the reciprocal of 7/3 is 3/7 (because 7/3 × 3/7 = 1).

• AWrong. −7/3 is the opposite (negative) of 2⅓, not its reciprocal.
• BCorrect. Write 2⅓ as 7/3, then flip it: 3/7.
• CWrong. 7/3 is 2⅓ written as an improper fraction; it still has to be flipped.
• DWrong. 7/2 flips the whole number and the fraction separately: 1/2 + 3.

Answer: A. Solve for y: 2y = −4x + 10, so y = −2x + 5. The slope is the coefficient of x, −2.

• ACorrect. y = −2x + 5, so the slope is −2.
• BWrong. 2 forgets that moving 4x to the other side makes it −4x.
• CWrong. 4 reads the coefficient of x before solving for y.
• DWrong. 5 is the y-intercept, not the slope.

Answer: D. There are 6 × 6 = 36 equally likely outcomes, and 6 of them add to 7 (1+6, 2+5, 3+4, 4+3, 5+2, 6+1), so the probability is 6/36 = 1/6.

• AWrong. 1/36 treats a sum of 7 as a single outcome; six different rolls add to 7.
• BWrong. 1/12 counts 1+6, 2+5 and 3+4 only once each (3/36); 1+6 and 6+1 are different rolls.
• CWrong. 1/11 treats the 11 possible sums (2 through 12) as equally likely; they are not.
• DCorrect. 6 of the 36 outcomes add to 7: 6/36 = 1/6.

Answer: C. Multiply every term by 3: x + 12 = 3x − 6. Then 18 = 2x, so x = 9.

• AWrong. 3 moves the −6 without changing its sign: 12 − 6 = 2x.
• BWrong. 5 multiplies only the x terms by 3 (x + 4 = 3x − 6) and leaves the 4 alone.
• CCorrect. Multiply by 3: x + 12 = 3x − 6, so 2x = 18 and x = 9.
• DWrong. 18 is the value of 2x; it still has to be divided by 2.

Answer: C. 6! ÷ 4! = (6 × 5 × 4!) ÷ 4! = 6 × 5 = 30.

• AWrong. 3/2 divides 6 by 4 and ignores the factorial signs.
• BWrong. 2 subtracts the numbers and takes (6 − 4)!; factorials do not subtract that way.
• CCorrect. 6! = 6 × 5 × 4!, so 6! ÷ 4! = 6 × 5 = 30.
• DWrong. 720 is 6! alone; it still has to be divided by 4! = 24.

Answer: D. Cross-multiply: 3(x + 1) = 6(x − 2), so 3x + 3 = 6x − 12. Then 15 = 3x and x = 5.

• AWrong. −4 cross-multiplies each numerator with its own denominator: 3(x − 2) = 6(x + 1).
• BWrong. −3 moves the −12 across without changing its sign: 3 − 12 = 3x.
• CWrong. 1 distributes only to x: 3x + 1 = 6x − 2, so 3 = 3x.
• DCorrect. 3(x + 1) = 6(x − 2) gives 3x + 3 = 6x − 12, so 3x = 15 and x = 5.

Answer: A. x² − y² = (x + y)(x − y), so 48 = 12(x − y) and x − y = 48 ÷ 12 = 4.

• ACorrect. x² − y² = (x + y)(x − y), so x − y = 48 ÷ 12 = 4.
• BWrong. 8 is the value of x (x + y = 12 and x − y = 4 give x = 8), not x − y.
• CWrong. 36 subtracts 12 from 48 instead of dividing.
• DWrong. 60 adds 48 and 12 instead of dividing.

Answer: A. Let the integers be n, n + 2 and n + 4. Then 3n + 6 = 81, so 3n = 75 and n = 25 (25 + 27 + 29 = 81).

• ACorrect. n + (n + 2) + (n + 4) = 81 gives 3n + 6 = 81 and n = 25.
• BWrong. 26 uses consecutive integers n, n + 1, n + 2 (3n + 3 = 81); odd integers are 2 apart, and 26 is even.
• CWrong. 27 is 81 ÷ 3, the middle integer, not the smallest.
• DWrong. 29 is the largest of the three, not the smallest.

Answer: A. A fuse contains a thin metal strip that melts when current exceeds its rating, opening the circuit.

• ACorrect. A fuse has a thin metal link that melts on overload, which opens the circuit and stops the current.
• BWrong. A capacitor stores electric charge; it does not melt to protect a circuit.
• CWrong. A resistor limits current, but it is not designed to open the circuit on an overload.
• DWrong. A transformer raises or lowers AC voltage; it gives no overload protection.

Answer: B. Unlike magnetic poles attract, so a north pole pulls on a south pole. Like poles repel.

• AWrong. Like poles repel, so two north poles push each other away.
• BCorrect. Unlike poles attract, so a north pole pulls on the south pole of another magnet.
• CWrong. Copper is not magnetic, so a magnet does not attract copper wire.
• DWrong. Aluminum is not magnetic, so a magnet does not pick up aluminum foil.

Answer: B. A resistor opposes current, so it is used to hold current to a safe or useful level.

• AWrong. A battery supplies the voltage that drives current; it does not limit it.
• BCorrect. A resistor opposes current flow, limiting how much current passes.
• CWrong. A switch only turns current fully on or fully off.
• DWrong. A transformer raises or lowers AC voltage; it is not used to set current levels.

Answer: B. US power is 60 hertz, or 60 cycles per second.

• AWrong. 50 Hz is the standard in Europe and much of the world, not the United States.
• BCorrect. US household power completes 60 cycles per second, or 60 Hz.
• CWrong. 100 Hz is not a standard power-line frequency anywhere.
• DWrong. 120 is the outlet voltage in volts, not the frequency.

Answer: A. A series circuit has only one path, so the same current flows through every component.

• ACorrect. With only one path for charge, the same current flows through every part of a series circuit.
• BWrong. The largest resistor has the largest voltage drop, but the current through it is the same as everywhere else.
• CWrong. Current divides only among parallel branches, not along a single series path.
• DWrong. Current is not used up; the same current that leaves the source returns to it.

Answer: C. Voltage is the potential difference, or electrical "pressure," that drives current through a circuit.

• AWrong. The rate of charge flow is current, measured in amperes.
• BWrong. Opposition to current is resistance, measured in ohms.
• CCorrect. Voltage is the potential difference, the "pressure" that pushes charge around a circuit.
• DWrong. Energy used over time is measured in watt-hours or kilowatt-hours, not volts.

Answer: D. A generator turns a coil in a magnetic field (or a magnet near a coil). The changing field induces a voltage in the coil.

• AWrong. A chemical reaction between different metals is how a battery makes voltage.
• BWrong. Storing charge on two plates is what a capacitor does; it does not produce energy.
• CWrong. A diode controls the direction of current; it does not produce voltage.
• DCorrect. Turning a coil in a magnetic field changes the field through the coil, which induces a voltage.

Answer: A. In the American Wire Gauge system, a larger number means a thinner wire. Thinner wire has more resistance and a lower current rating.

• ACorrect. A higher AWG number means a thinner wire, which has more resistance and a lower safe current.
• BWrong. The gauge scale runs backward: larger numbers are thinner wires, not thicker ones.
• CWrong. Thinner wire has more resistance and heats up sooner, so it carries less current, not more.
• DWrong. AWG numbers describe the conductor's diameter, not the insulation.

Answer: C. The open switch breaks only the branch that holds L3. Current still flows from the battery through L1 and then through L2, so L1 and L2 light.

• AWrong. The open switch breaks only the L3 branch; the path through L1 and L2 is still complete.
• BWrong. L1 is in series with the battery, so any current through L2 must also pass through L1.
• CCorrect. Current flows through L1 and then L2; only the L3 branch is broken by the open switch.
• DWrong. L3 is in series with the open switch, so no current reaches it.

Answer: B. A rectifier, usually built from diodes, lets current pass in only one direction, turning AC into DC.

• AWrong. An inverter does the opposite job: it changes DC into AC.
• BCorrect. A rectifier uses diodes to pass current one way only, turning AC into DC.
• CWrong. A transformer changes the AC voltage level, but its output is still AC.
• DWrong. An oscillator produces an AC signal from a DC supply.

Answer: B. The circuit can supply 120 V × 15 A = 1,800 W at its rating, so 1,800 − 1,500 = 300 W remain. (In real wiring, a load that runs for hours should stay under 80% of the rating, 1,440 W, so this circuit is already fully loaded in practice.)

• AWrong. 150 W comes from using 110 V instead of 120 V (110 × 15 = 1,650 W, minus 1,500).
• BCorrect. Capacity is 120 V × 15 A = 1,800 W; 1,800 − 1,500 = 300 W is left.
• CWrong. 1,500 W would add a second heater and bring the load to 3,000 W, far over the 1,800-W limit.
• DWrong. 1,800 W is the whole circuit capacity; it ignores the 1,500 W already in use.

Answer: A. Total resistance = V ÷ I = 24 ÷ 2 = 12 Ω. Series resistances add, so R2 = 12 − 4 = 8 Ω.

• ACorrect. R total = 24 ÷ 2 = 12 Ω, and R2 = 12 − 4 = 8 Ω.
• BWrong. 12 Ω is the total resistance of the circuit, not R2 alone.
• CWrong. 16 is the voltage across R2 in volts (2 A × 8 Ω), not its resistance.
• DWrong. 48 Ω multiplies volts by amps (24 × 2); that product is power in watts.

Answer: D. Changing current in the coil changes its magnetic field, which induces a voltage that opposes the change. An inductor stores energy in a magnetic field.

• AWrong. Blocking current in one direction is what a diode does.
• BWrong. Changing AC into DC is the job of a rectifier.
• CWrong. Storing energy in an electric field between plates describes a capacitor; an inductor stores energy in a magnetic field.
• DCorrect. A changing current changes the coil's magnetic field, which induces a voltage that opposes the change.

Answer: C. R = V² ÷ P gives 240 Ω for the 60-W lamp and 144 Ω for the 100-W lamp. In series the current is the same, so P = I²R is larger in the 60-W lamp (about 23 W versus 14 W).

• AWrong. A lamp's watt rating applies only at full 120 V; in series the 100-W lamp, with less resistance, gets only about 14 W.
• BWrong. The current is the same, but P = I²R also depends on resistance, which differs (240 Ω versus 144 Ω).
• CCorrect. The 60-W lamp has more resistance (240 Ω), so with the same current it takes more power, about 23 W.
• DWrong. The voltage divides unequally (75 V and 45 V), and both lamps still glow, only dimly.

Answer: D. Capacitive reactance is Xc = 1 ÷ (2πfC), so it falls as frequency rises and more current flows.

• AWrong. Rising opposition with frequency is how an inductor behaves, not a capacitor.
• BWrong. Opposition that ignores frequency describes a resistor.
• CWrong. Reactance falls as frequency rises but never reaches zero at any real frequency.
• DCorrect. Xc = 1 ÷ (2πfC), so a higher frequency gives lower reactance and more current.

Answer: A. The picture shows a flat rotor bolted to the wheel hub with a caliper clamped over its edge. The caliper squeezes pads against the rotor, which makes this a disc brake.

• ACorrect. A flat rotor with a caliper straddling its edge is a disc brake; the caliper squeezes pads against both faces of the rotor.
• BWrong. A drum brake is closed inside a round drum, with curved shoes pushed outward against it; no caliper is visible.
• CWrong. A band brake wraps a flexible band around a drum, as in some automatic transmissions; it has no rotor or caliper.
• DWrong. An exhaust brake is a valve in a diesel’s exhaust that slows the engine; it is not mounted at the wheel.

Answer: B. Pressing the clutch pedal separates the clutch disc from the flywheel, so the driver can change gears or stop without stalling.

• AWrong. The brakes are applied with the brake pedal; the clutch pedal is not connected to them.
• BCorrect. Pressing the pedal pulls the clutch disc away from the flywheel, disconnecting the engine from the transmission so gears can be changed.
• CWrong. Differential locks are worked by a separate switch or lever on some off-road vehicles, not by the clutch pedal.
• DWrong. Fuel flow is controlled by the accelerator pedal.

Answer: A. This is a cross-shaped (four-way) lug wrench. Each arm ends in a different-size socket that fits the lug nuts holding a wheel on, and the long arms give leverage.

• ACorrect. The sockets on the ends of the arms fit wheel lug nuts, and the cross shape gives two-handed leverage to loosen or tighten them.
• BWrong. Tread depth is measured with a small tread-depth gauge that has a sliding probe.
• CWrong. Tire beads are pried off with tire irons, which are flat bars without sockets.
• DWrong. Alignment is adjusted at the tie rods and suspension using an alignment machine, not with a lug wrench.

Answer: C. The thermostat stays closed until the engine warms up, then opens to let coolant flow to the radiator. This helps the engine reach operating temperature quickly.

• AWrong. The water pump moves the coolant; the thermostat only opens or closes a passage.
• BWrong. Oil temperature is read by a sensor; the thermostat works on the coolant, not the oil.
• CCorrect. The thermostat stays shut while the engine is cold and opens once it warms up, sending coolant to the radiator.
• DWrong. Pressure in the cooling system is held by the radiator cap.

Answer: A. Air compresses, unlike brake fluid, so trapped air makes the pedal feel spongy. Warped rotors cause a pulsing pedal instead.

• ACorrect. Air bubbles squeeze smaller when the pedal is pushed, unlike brake fluid, so the pedal feels soft; bleeding the brakes removes the air.
• BWrong. Warped rotors make the pedal pulse or vibrate, not feel spongy.
• CWrong. Low tire pressure affects handling and tire wear, not the feel of the brake pedal.
• DWrong. A worn wheel bearing makes a humming or grinding noise that changes with speed.

Answer: B. Rapid clicking means the starter solenoid is getting enough power to click but not enough to turn the starter motor, which points to a weak battery or poor connection.

• AWrong. A clogged fuel filter can make an engine crank but not start; it does not stop the engine from cranking.
• BCorrect. Rapid clicking means the starter solenoid gets enough current to click but the starter motor does not get enough to turn, which points to a weak battery or a poor connection.
• CWrong. Worn spark plugs cause hard starting or misfires, but the engine still cranks.
• DWrong. A stuck thermostat causes overheating or slow warm-up, not a no-crank.

Answer: C. About 14.7 parts air to 1 part fuel by weight burns gasoline completely. Richer mixtures have less air; leaner mixtures have more.

• AWrong. 7:1 is far too rich; that much fuel would leave heavy black smoke and unburned gasoline.
• BWrong. 10:1 is still rich, with more fuel than the air can burn completely.
• CCorrect. About 14.7 parts air to 1 part gasoline by weight burns all the fuel with no oxygen left over.
• DWrong. 20:1 is lean; the extra air can cause misfires and high combustion temperatures.

Answer: D. The last connection often makes a small spark. Making it on bare engine metal, away from the dead battery, keeps that spark away from the hydrogen gas a battery can give off.

• AWrong. The dead battery’s positive terminal gets the first clamp, not the last.
• BWrong. The good battery’s positive terminal is the second connection, made right after the dead battery’s positive.
• CWrong. The good battery’s negative terminal is the third connection; the last clamp goes to a ground point on the dead car.
• DCorrect. A ground point on the dead car’s engine completes the circuit while keeping the final spark away from battery gases.

Answer: D. Pressure raises the boiling point of the coolant, so pressurized coolant can run hotter than 212 °F without boiling over.

• AWrong. Coolant and oil are kept separate; coolant in the oil is a sign of a failed gasket.
• BWrong. Freeze protection comes from the antifreeze mixed into the water; pressure has almost no effect on the freezing point.
• CWrong. Water pump speed is set by engine speed through the belt, not by system pressure.
• DCorrect. Each pound of pressure raises the boiling point roughly 3 °F, so coolant under a 15-psi cap can run well above 212 °F without boiling.

Answer: B. A full four-stroke cycle takes two crankshaft revolutions, and each valve opens once per cycle. So the camshaft turns once for every two crankshaft turns, which is half the speed.

• AWrong. At one-quarter speed, each valve would open only once every four crankshaft turns, which is two full cycles.
• BCorrect. One cycle takes two crankshaft turns and each valve opens once per cycle, so the camshaft turns at half crankshaft speed.
• CWrong. At the same speed, each valve would open on every crankshaft turn, twice per cycle.
• DWrong. At twice the speed, each valve would open four times per cycle.

Answer: A. A claw hammer has a split, curved claw that grips a nail head and levers it out. A ball-peen hammer is for shaping metal.

• ACorrect. The split, curved claw slips under a nail head and levers the nail out.
• BWrong. A ball-peen hammer has a rounded peen for shaping metal and setting rivets; it has no claw.
• CWrong. A rubber mallet taps parts together without marring them; it cannot grip a nail.
• DWrong. A sledgehammer is a heavy, long-handled hammer for demolition and driving stakes.

Answer: B. Its one-piece frame is shaped like the letter C, and a screw with a swivel pad closes the opening. That makes it a C-clamp.

• AWrong. A bar clamp has two jaws that slide along a long, flat steel bar.
• BCorrect. The C-shaped frame with a screw and swivel pad across its opening is a C-clamp.
• CWrong. A spring clamp looks like large clothespin jaws held shut by a coiled spring.
• DWrong. A pipe clamp has its jaws mounted on a length of pipe, so it can span wide work.

Answer: A. This is a hacksaw. Its rigid frame holds a thin blade with many small, hardened teeth under tension, which is made for cutting metal.

• ACorrect. The frame keeps a fine-toothed, hardened blade tight so it can cut through metal rod, pipe, and bolts.
• BWrong. Curves in thin wood are cut with a coping saw, whose very thin blade sits in a deep frame.
• CWrong. Ripping along the grain calls for a ripsaw’s large, chisel-like teeth; a hacksaw’s fine teeth clog in wood.
• DWrong. Drywall is cut with a utility knife or a pointed drywall saw.

Answer: B. The tenon is the projection and the mortise is the hole it fits into. A butt joint simply places two ends or faces together.

• AWrong. A butt joint just places two ends or faces together, with no projection or hole.
• BCorrect. The tenon is the rectangular projection and the mortise is the matching hole it fits into.
• CWrong. A lap joint overlaps two pieces, often with half the thickness cut away from each.
• DWrong. A miter joint joins two pieces cut at matching angles, usually 45°, as in a picture frame.

Answer: D. Long, thin jaws that taper to a point mark needle-nose pliers. They grip small parts and bend wire in tight spots.

• AWrong. Slip-joint pliers have short, broad jaws and a pivot that shifts to a second position for wider grips.
• BWrong. Locking pliers have an adjusting screw at the end of one handle and a lever that locks the jaws shut.
• CWrong. Tongue-and-groove pliers have angled jaws and a long, grooved pivot for gripping pipes and large nuts.
• DCorrect. The long, pointed jaws are the mark of needle-nose pliers, made for reaching into tight places.

Answer: B. A deep, U-shaped frame holding a very thin blade, with a straight handle, is a coping saw. The thin blade can follow tight curves in wood.

• AWrong. A backsaw has a wide, rectangular blade stiffened by a metal spine along its top edge, with no frame.
• BCorrect. The deep, narrow frame and very thin blade identify a coping saw, used for curves and detailed cuts.
• CWrong. A hacksaw has a shallower, rigid frame, usually with a pistol grip, and a wider blade for metal.
• DWrong. A keyhole saw has a narrow, pointed blade that sticks straight out from a handle, with no frame.

Answer: C. Flux removes and prevents oxides on the copper as it heats, letting molten solder wet the surfaces and flow into the joint.

• AWrong. The solder sets as the joint cools on its own; flux does not speed that up.
• BWrong. Flux does not insulate the pipe; the copper has to get hot for the solder to melt.
• CCorrect. Flux cleans off and blocks oxides as the copper heats, so molten solder can wet the metal and flow into the joint.
• DWrong. Solder is pulled into a tight fit by capillary action; flux cannot fill large gaps.

Answer: B. Annealing heats steel and lets it cool slowly, leaving it softer and easier to cut or bend. Quick quenching hardens steel, and reheating hardened steel to a lower temperature is tempering.

• AWrong. Heating and then quenching quickly hardens steel, which is the opposite of annealing.
• BCorrect. Annealing heats steel and lets it cool slowly, leaving it softer and easier to cut or bend.
• CWrong. Coating steel with zinc to prevent rust is galvanizing.
• DWrong. Reheating hardened steel to a lower temperature to reduce brittleness is tempering.

Answer: C. Board feet = thickness (in) × width (in) × length (ft) ÷ 12 = 2 × 6 × 12 ÷ 12 = 12. Board feet are figured from the nominal size.

• AWrong. 6 leaves out the 2-inch thickness: 6 × 12 ÷ 12 = 6.
• BWrong. 8.25 uses the actual 1½ × 5½ in size, but lumber is sold in board feet figured from its nominal size.
• CCorrect. Board feet = 2 × 6 × 12 ÷ 12 = 12.
• DWrong. 144 forgets to divide by 12: 2 × 6 × 12 = 144.

Answer: A. The right-triangle symbol stands for a fillet weld. It sits below the reference line, and a symbol below the line applies to the arrow side of the joint.

• ACorrect. The triangle means a fillet weld, and placing it below the reference line means the arrow side.
• BWrong. For the other side, the triangle would be drawn above the reference line.
• CWrong. Groove welds use V, bevel, U, or square-groove symbols, not a triangle.
• DWrong. A plug weld is shown by a small rectangle, and a symbol below the line means the arrow side.

Answer: C. A single fixed pulley has one supporting strand, so its mechanical advantage is 1. It only changes the direction of the pull: F = 80 lb.

• AWrong. 20 lb divides by 4, as if four strands held the load; a single fixed pulley gives no force advantage.
• BWrong. 40 lb assumes the pulley halves the load, which only a movable pulley does; this pulley is fixed.
• CCorrect. A single fixed pulley only changes the direction of the pull, so F equals the load: 80 lb.
• DWrong. 160 lb doubles the load; a frictionless pulley never makes you pull harder than the load.

Answer: B. Friction acts along the surface in the direction opposite to the motion. The box slides right, so friction points left (arrow B).

• AWrong. Arrow A points up, the direction of the floor’s supporting force, not friction.
• BCorrect. Friction acts along the floor, opposite to the motion, so it points left: arrow B.
• CWrong. Arrow C points down, the direction of gravity (the box’s weight).
• DWrong. Arrow D is the direction the box is moving; friction acts against the motion.

Answer: D. Heat is conducted along the metal from the hot end toward the cool end. The wax nearest the flame, at D, melts first.

• AWrong. A is farthest from the flame, so its tack falls off last.
• BWrong. B is on the far half of the rod from the flame; heat reaches it after C and D.
• CWrong. C is farther from the flame than D, so heat reaches it later.
• DCorrect. Heat travels along the rod from the flame, so the wax nearest the flame, at D, melts first.

Answer: B. A floating block displaces its own weight of water. Block B sits deeper, so it pushes aside more water and must weigh more.

• AWrong. Block A floats higher because it displaces less water, which means it is lighter, not heavier.
• BCorrect. B sits deeper and displaces more water, and a floating object weighs the same as the water it displaces.
• CWrong. Equal size does not mean equal weight; blocks of equal weight would float at the same depth.
• DWrong. The depth at which each block floats shows its weight, so the figure is enough to decide.

Answer: C. The string was the only thing pulling the ball toward the center. Once it breaks, the ball keeps moving in a straight line in the direction it was already going, along path C.

• AWrong. Path A points straight away from the pivot, but nothing pushes the ball outward when the string breaks.
• BWrong. Path B keeps curving, but a curved path needs the string’s inward pull, which is gone.
• CCorrect. With no inward pull, the ball moves in a straight line in the direction it was moving at that instant: path C.
• DWrong. Path D is a straight line in the wrong direction; the ball keeps moving the way it was already going.

Answer: C. With the load centered, its turning effect about each post is the same, so each post holds up half of it. How thick a post is does not change how much load it carries.

• AWrong. A thicker post is stronger, but strength does not change how the load is shared; only the load’s position does.
• BWrong. Post B would carry more only if the load were closer to B; it sits exactly halfway.
• CCorrect. The load is 5 ft from each post, so each post supports half of it.
• DWrong. The figure gives everything needed: the load’s position alone sets each post’s share.

Answer: B. Each mesh reverses the direction: A clockwise, B counterclockwise, C clockwise, D counterclockwise. Only C matches A.

• AWrong. B meshes directly with A, so it turns the opposite way (counterclockwise).
• BCorrect. Each mesh reverses direction: A clockwise, B counterclockwise, C clockwise, D counterclockwise. Only C matches A.
• CWrong. D is three meshes away from A; an odd number of meshes reverses the direction, so D turns counterclockwise.
• DWrong. B and D both turn counterclockwise, the opposite of A; they are the gears that differ from A.

Answer: D. Pressure is the same throughout the fluid: 20 ÷ 2 = 10 lb per in². On the large piston, 10 × 30 = 300 lb.

• AWrong. 1.33 lb applies the area ratio backwards (20 × 2 ÷ 30); the larger piston gets more force, not less.
• BWrong. 20 lb assumes the fluid passes on the same force; it passes on the same pressure, and the large piston has more area.
• CWrong. 40 lb multiplies the force by the small piston’s area (20 × 2) instead of dividing to get the pressure.
• DCorrect. Pressure = 20 ÷ 2 = 10 lb per in², and the large piston gets 10 × 30 = 300 lb.

Answer: B. The belt moves at the same speed on both pulleys, so rpm × diameter is equal: 300 × 10 = B × 4, and B = 750 rpm.

• AWrong. 120 rpm flips the ratio (300 × 4 ÷ 10); the smaller pulley must turn faster, not slower.
• BCorrect. The belt moves at the same speed on both pulleys: 300 × 10 = B × 4, so B = 750 rpm.
• CWrong. 1,200 rpm multiplies by B’s diameter (300 × 4) instead of by the ratio 10 ÷ 4.
• DWrong. 3,000 rpm multiplies 300 by A’s 10-in diameter but never divides by B’s 4 in.

Answer: A. A wheelbarrow is a second-class lever with the axle as the fulcrum: F × 4.5 = 180 × 1.5 = 270, so F = 60 lb.

• ACorrect. The axle is the fulcrum: F × 4.5 = 180 × 1.5 = 270, so F = 60 lb.
• BWrong. 120 lb is the part of the load the wheel carries (180 − 60), not the lift at the handles.
• CWrong. 180 lb assumes you must lift the whole load, but the axle carries part of it and the long handles give an advantage of 3.
• DWrong. 540 lb applies the arm ratio backwards (180 × 4.5 ÷ 1.5).

Answer: C. Left turning effect: 30 × 6 + 20 × 3 = 240 ft·lb. Right: W × 5 = 240, so W = 48 lb.

• AWrong. 36 lb leaves out the 20-lb weight’s turning effect (180 ÷ 5).
• BWrong. 40 lb divides the 240 ft·lb by 6 ft, the distance of the far left weight, instead of by W’s 5 ft.
• CCorrect. Left side: 30 × 6 + 20 × 3 = 240 ft·lb, and W × 5 = 240, so W = 48 lb.
• DWrong. 60 lb treats both left weights as if they sat 6 ft out (50 × 6 ÷ 5).

Answer: B. Mechanical advantage = handle distance ÷ lift per turn = 60 ÷ 0.25 = 240. Force = 3,000 ÷ 240 = 12.5 lb.

• AWrong. 1.25 lb misplaces the decimal point in 3,000 ÷ 240.
• BCorrect. Mechanical advantage = 60 ÷ 0.25 = 240, so F = 3,000 ÷ 240 = 12.5 lb.
• CWrong. 50 lb divides 3,000 by the 60-in handle travel alone, leaving out the 1/4-in lift per turn.
• DWrong. 750 lb multiplies 3,000 by 1/4, using only the thread spacing and ignoring the 60-in handle travel.

Answer: C. The bottom spring carries all 20 lb and stretches 4 in. Each top spring carries 10 lb and stretches 2 in. Total drop = 4 + 2 = 6 in.

• AWrong. 2 in counts only the top pair of springs; the bottom spring also stretches.
• BWrong. 4 in counts only the bottom spring; the top pair stretches too, and the weight drops by both amounts.
• CCorrect. The bottom spring holds 20 lb and stretches 4 in; each top spring holds 10 lb and stretches 2 in: 4 + 2 = 6 in.
• DWrong. 8 in treats the top pair as if it carried the full 20 lb like a single spring (4 + 4).

Answer: B. Take turning effects about the left end: rod 4 × 1.5 = 6 and right weight 2 × 3 = 6, total 12 ft·lb. Divide by the total weight, 12 lb: the balance point is 1 ft from the left end.

• AWrong. 0.75 ft ignores the rod’s own weight: (2 × 3) ÷ 8 = 0.75.
• BCorrect. About the left end: 4 × 1.5 + 2 × 3 = 12 ft·lb, and 12 ÷ 12 lb total = 1 ft.
• CWrong. 1.5 ft is the middle of the rod, the balance point only if the two end weights were equal.
• DWrong. 2 ft divides 12 ft·lb by 6 lb, leaving the rod and the 2-lb weight out of the total weight.

Answer: A. B turns 240 × 12 ÷ 36 = 80 rpm, and C turns with B at 80 rpm. D turns 80 × 12 ÷ 48 = 20 rpm.

• ACorrect. B turns 240 × 12 ÷ 36 = 80 rpm, C turns with it on the shared shaft, and D turns 80 × 12 ÷ 48 = 20 rpm.
• BWrong. 60 rpm skips the middle pair and uses only A and D (240 × 12 ÷ 48).
• CWrong. 80 rpm is the speed of B and C on the shared shaft, not of D.
• DWrong. 180 rpm uses B’s 36 teeth against D’s 48 (240 × 36 ÷ 48); C, not B, drives D.

Answer: B. The loose pieces are four quarters of a circle. Only one choice is cut into exactly those pieces at the same size; the others need a piece that is not in the box.

• AWrong. This circle is cut into six sixths of a circle, but the box holds four quarters of a circle.
• BCorrect. This circle is cut into four quarters of a circle: exactly the pieces in the box, at the same size.
• CWrong. This circle is cut into two halves of a circle, but the box holds four quarters of a circle.
• DWrong. This circle is cut into a two-thirds piece and a one-third piece of a circle, but the box holds four quarters of a circle.

Answer: C. Point A is at the edge of the circle and point B is at the middle of a side of the square. Only one choice joins exactly those two points — the shapes may be turned, which does not change where the line attaches.

• AWrong. The line leaves the circle at the center, but A is at the edge; and the line meets the square at a corner, but B is at the middle of a side.
• BWrong. The line leaves the circle at the center, but A is at the edge.
• CCorrect. The line joins the edge of the circle (A) to the middle of a side of the square (B), exactly as marked. The shapes are only turned, which doesn't change where the line attaches.
• DWrong. The line meets the square at a corner, but B is at the middle of a side.

Answer: A. The loose pieces are a three-quarter piece and a one-quarter piece of a circle. Only one choice is cut into exactly those pieces at the same size; the others need a piece that is not in the box.

• ACorrect. This circle is cut into a three-quarter piece and a one-quarter piece of a circle: exactly the pieces in the box, at the same size.
• BWrong. This circle is cut into six sixths of a circle, but the box holds a three-quarter piece and a one-quarter piece of a circle.
• CWrong. This circle is cut into four quarters of a circle, but the box holds a three-quarter piece and a one-quarter piece of a circle.
• DWrong. This circle is cut into two thirds and two sixths of a circle, but the box holds a three-quarter piece and a one-quarter piece of a circle.

Answer: A. The loose pieces are six sixths of a circle. Only one choice is cut into exactly those pieces at the same size; the others need a piece that is not in the box.

• ACorrect. This circle is cut into six sixths of a circle: exactly the pieces in the box, at the same size.
• BWrong. This circle is cut into two halves of a circle, but the box holds six sixths of a circle.
• CWrong. This circle is cut into a three-quarter piece and a one-quarter piece of a circle, but the box holds six sixths of a circle.
• DWrong. This circle is cut into a two-thirds piece and a one-third piece of a circle, but the box holds six sixths of a circle.

Answer: B. Point A is at a corner of the square and point B is at a corner of the square. Only one choice joins exactly those two points — the shapes may be turned, which does not change where the line attaches.

• AWrong. The line leaves the square at the middle of a side, but A is at a corner; and the line meets the square at the middle of a side, but B is at a corner.
• BCorrect. The line joins a corner of the square (A) to a corner of the square (B), exactly as marked. The shapes are only turned, which doesn't change where the line attaches.
• CWrong. The line leaves the square at the middle of a side, but A is at a corner.
• DWrong. The line meets the square at the middle of a side, but B is at a corner.

Answer: C. The loose pieces are a right triangle and a trapezoid that make a rectangle. Only one choice is cut into exactly those pieces at the same size; the others need a piece that is not in the box.

• AWrong. This rectangle is cut into four rectangles, but the box holds a right triangle and a trapezoid.
• BWrong. This rectangle is cut into a square and two right triangles, but the box holds a right triangle and a trapezoid.
• CCorrect. This rectangle is cut into a right triangle and a trapezoid: exactly the pieces in the box, at the same size.
• DWrong. This rectangle is cut into three right triangles, but the box holds a right triangle and a trapezoid.

Answer: D. The loose pieces are two right triangles that make a triangle. Only one choice is cut into exactly those pieces at the same size; the others need a piece that is not in the box.

• AWrong. This triangle is cut into an equilateral triangle and a trapezoid, but the box holds two right triangles.
• BWrong. This triangle is cut into three triangles, but the box holds two right triangles.
• CWrong. This triangle is cut into four equilateral triangles, but the box holds two right triangles.
• DCorrect. This triangle is cut into two right triangles: exactly the pieces in the box, at the same size.

Answer: D. Point A is at the edge of the circle and point B is at the edge of the circle. Only one choice joins exactly those two points — the shapes may be turned, which does not change where the line attaches.

• AWrong. The line leaves the circle at the center, but A is at the edge.
• BWrong. The line meets the circle at the center, but B is at the edge.
• CWrong. The line leaves the circle at the center, but A is at the edge; and the line meets the circle at the center, but B is at the edge.
• DCorrect. The line joins the edge of the circle (A) to the edge of the circle (B), exactly as marked. The shapes are only turned, which doesn't change where the line attaches.

Answer: C. The loose pieces are four rectangles that make a rectangle. Only one choice is cut into exactly those pieces at the same size; the others need a piece that is not in the box.

• AWrong. This rectangle is cut into three right triangles, but the box holds four rectangles.
• BWrong. This rectangle is cut into a square and two right triangles, but the box holds four rectangles.
• CCorrect. This rectangle is cut into four rectangles: exactly the pieces in the box, at the same size.
• DWrong. This rectangle is cut into a right triangle and a trapezoid, but the box holds four rectangles.

Answer: B. Point A is at the square corner of the right triangle and point B is at the center of the circle. Only one choice joins exactly those two points — the shapes may be turned, which does not change where the line attaches.

• AWrong. The line meets the circle at the edge, but B is at the center.
• BCorrect. The line joins the square corner of the right triangle (A) to the center of the circle (B), exactly as marked. The shapes are only turned, which doesn't change where the line attaches.
• CWrong. The line leaves the right triangle at the middle of a side, but A is at the square corner.
• DWrong. The line leaves the right triangle at the center, but A is at the square corner.

Answer: C. The loose pieces are a right triangle and a five-sided piece that make a square. Only one choice is cut into exactly those pieces at the same size; the others need a piece that is not in the box.

• AWrong. This square is cut into two rectangles, but the box holds a right triangle and a five-sided piece.
• BWrong. This square is cut into a right triangle and a trapezoid, but the box holds a right triangle and a five-sided piece.
• CCorrect. This square is cut into a right triangle and a five-sided piece: exactly the pieces in the box, at the same size.
• DWrong. This square is cut into two right triangles, but the box holds a right triangle and a five-sided piece.

Answer: D. Point A is at the center of the trapezoid and point B is at the center of the right triangle. Only one choice joins exactly those two points — the shapes may be turned, which does not change where the line attaches.

• AWrong. The line meets the right triangle at the middle of the shortest side, but B is at the center.
• BWrong. The line meets the right triangle at the middle of the longest side, but B is at the center.
• CWrong. The line leaves the trapezoid at the sharpest corner, but A is at the center.
• DCorrect. The line joins the center of the trapezoid (A) to the center of the right triangle (B), exactly as marked. The shapes are only turned, which doesn't change where the line attaches.

Answer: A. Point A is at the widest corner of the trapezoid and point B is at the center of the circle. Only one choice joins exactly those two points — the shapes may be turned, which does not change where the line attaches.

• ACorrect. The line joins the widest corner of the trapezoid (A) to the center of the circle (B), exactly as marked. The shapes are only turned, which doesn't change where the line attaches.
• BWrong. The line meets the circle at the edge, but B is at the center.
• CWrong. The line leaves the trapezoid at the center, but A is at the widest corner.
• DWrong. The line leaves the trapezoid at the middle of the shortest side, but A is at the widest corner.

Answer: C. Point A is at the sharpest corner of the trapezoid and point B is at the middle of a side of the hexagon. Only one choice joins exactly those two points — the shapes may be turned, which does not change where the line attaches.

• AWrong. The line leaves the trapezoid at the middle of the shortest side, but A is at the sharpest corner.
• BWrong. The line leaves the trapezoid at the center, but A is at the sharpest corner.
• CCorrect. The line joins the sharpest corner of the trapezoid (A) to the middle of a side of the hexagon (B), exactly as marked. The shapes are only turned, which doesn't change where the line attaches.
• DWrong. The line leaves the trapezoid at the middle of a side, but A is at the sharpest corner.

Answer: C. Point A is at the middle of a side of the trapezoid and point B is at the middle of the longest side of the rectangle. Only one choice joins exactly those two points — the shapes may be turned, which does not change where the line attaches.

• AWrong. The line meets the rectangle at a corner, but B is at the middle of the longest side.
• BWrong. The line leaves the trapezoid at the middle of the shortest side, but A is at the middle of a side.
• CCorrect. The line joins the middle of a side of the trapezoid (A) to the middle of the longest side of the rectangle (B), exactly as marked. The shapes are only turned, which doesn't change where the line attaches.
• DWrong. The line leaves the trapezoid at the widest corner, but A is at the middle of a side.