ASVAB Practice Exam 1

Answer: A. The heart is a muscular pump whose contractions push blood through the arteries and veins.

• ACorrect. The heart is a muscular pump; each contraction pushes blood out through the arteries and around the body.
• BWrong. The liver filters the blood and makes bile, but it does not pump blood.
• CWrong. The lungs load oxygen into the blood and remove carbon dioxide; the heart does the pumping.
• DWrong. The stomach churns and digests food; it plays no part in moving blood.

Answer: A. Every living thing is made of one or more cells, the smallest units that carry out life processes.

• ACorrect. Every living thing is made of one or more cells, the smallest units that carry out all life processes.
• BWrong. Atoms make up all matter, living or not, but a single atom is not alive.
• CWrong. A tissue is a group of similar cells working together, so it is built from cells.
• DWrong. An organ, such as the heart, is built from several tissues; many living things, like bacteria, have no organs at all.

Answer: B. Producers, such as plants and algae, make their own food by photosynthesis.

• AWrong. A consumer cannot make its own food; it gets energy by eating other organisms.
• BCorrect. Producers, such as plants and algae, capture sunlight and make their own food by photosynthesis.
• CWrong. A decomposer, such as a fungus or many bacteria, gets energy by breaking down dead matter and wastes.
• DWrong. A predator is a consumer that hunts and eats other animals.

Answer: C. Photosynthesis uses carbon dioxide and water, powered by light, to make sugar and release oxygen.

• AWrong. Oxygen is given off by photosynthesis; plants take it in only for respiration.
• BWrong. Air is mostly nitrogen, but plants cannot use nitrogen gas; they get nitrogen from nitrates in the soil.
• CCorrect. Photosynthesis combines carbon dioxide from the air with water, using light energy, to make sugar and release oxygen.
• DWrong. Plants get the hydrogen they need by splitting water taken up by the roots; air holds almost no hydrogen gas.

Answer: B. One kilometer is 1,000 meters, so 2.5 × 1,000 = 2,500 m.

• AWrong. 250 m uses 100 meters per kilometer; a kilometer is 1,000 meters.
• BCorrect. One kilometer is 1,000 meters, so 2.5 km × 1,000 = 2,500 m.
• CWrong. 25,000 m uses 10,000 meters per kilometer, moving the decimal point one place too far.
• DWrong. 250,000 is the number of centimeters in 2.5 km (2,500 m × 100), not meters.

Answer: B. The troposphere is the lowest layer and holds nearly all of the air’s water vapor, so clouds, rain, and storms form there.

• AWrong. The stratosphere, just above the troposphere, holds the ozone layer and is very dry, with few clouds.
• BCorrect. The troposphere is the lowest layer and holds nearly all of the air’s water vapor, so clouds, rain, and storms form there.
• CWrong. The mesosphere is where most meteors burn up; its air is far too thin and dry for weather.
• DWrong. The thermosphere is a very thin, high layer where auroras glow and many satellites orbit.

Answer: D. Cell clusters in the pancreas release insulin, which helps body cells take in glucose from the blood.

• AWrong. The liver stores glucose as glycogen and releases it when blood sugar falls, but it does not make insulin.
• BWrong. The gallbladder stores bile and releases it into the small intestine to help digest fats; it makes no insulin.
• CWrong. The thyroid makes hormones that set the body’s metabolic rate, not insulin.
• DCorrect. Cell clusters in the pancreas (the islets) release insulin, which lets body cells take in glucose and so lowers blood sugar.

Answer: B. Egg and sperm cells are made by meiosis, which halves the chromosome number: 46 ÷ 2 = 23. Fertilization restores 46.

• AWrong. 22 is the number of non-sex chromosomes in an egg; the egg also carries one X chromosome, for 23 in all.
• BCorrect. Meiosis halves the chromosome number, so an egg has 46 ÷ 2 = 23; joining with a sperm’s 23 restores 46.
• CWrong. 46 is the number in ordinary body cells; if eggs and sperm had 46, each child would get 92.
• DWrong. 92 doubles the body-cell number; sex cells have half as many chromosomes, not twice as many.

Answer: A. A light-year is the distance light travels in one year, about 9.5 trillion kilometers (5.9 trillion miles).

• ACorrect. A light-year is the distance light travels in one year, about 9.5 trillion kilometers (5.9 trillion miles).
• BWrong. Despite the word “year” in its name, a light-year is not a length of time.
• CWrong. The speed of light is about 300,000 kilometers per second; a light-year is how far light goes at that speed in a year.
• DWrong. Astronomers rate a star’s brightness on the magnitude scale, not in light-years.

Answer: D. The cerebellum, at the back of the brain, fine-tunes movement, posture, and balance.

• AWrong. The cerebrum, the largest part of the brain, handles thinking, memory, the senses, and starting voluntary movements.
• BWrong. The medulla oblongata controls automatic functions such as breathing, heart rate, and blood pressure.
• CWrong. The hypothalamus regulates body temperature, hunger, and thirst, and it controls the pituitary gland.
• DCorrect. The cerebellum, at the back of the brain, coordinates balance, posture, and smooth, precise movements.

Answer: D. At a divergent boundary plates pull apart and new crust forms, as along mid-ocean ridges.

• AWrong. At a convergent boundary plates move toward each other and collide, building mountains or trenches.
• BWrong. At a transform boundary plates slide past each other sideways, as along the San Andreas Fault.
• CWrong. A subduction zone is where one plate sinks beneath another at a convergent boundary, not where plates separate.
• DCorrect. At a divergent boundary plates pull apart and rising magma forms new crust, as along the Mid-Atlantic Ridge.

Answer: D. Wave speed = frequency × wavelength = 5 × 4 = 20 m/s.

• AWrong. 0.8 m/s divides wavelength by frequency (4 ÷ 5); speed is the two multiplied.
• BWrong. 1.25 m/s divides frequency by wavelength (5 ÷ 4); speed is the two multiplied.
• CWrong. 9 m/s adds frequency and wavelength (5 + 4), which does not give a speed.
• DCorrect. Wave speed = frequency × wavelength = 5 waves per second × 4 meters = 20 m/s.

Answer: C. KE = ½mv² = ½ × 2 × 3² = ½ × 2 × 9 = 9 J.

• AWrong. 3 J comes from ½ × 2 × 3, which forgets to square the speed.
• BWrong. 6 J is mass × speed (2 × 3), which is the ball’s momentum in kg·m/s, not its kinetic energy.
• CCorrect. Kinetic energy is ½mv² = ½ × 2 × 3² = ½ × 2 × 9 = 9 J.
• DWrong. 18 J is m × v² (2 × 9), which leaves out the ½ in the formula.

Answer: B. At constant temperature, pressure × volume stays the same (Boyle’s law): 2 × 6 = 3 × V, so V = 12 ÷ 3 = 4 L.

• AWrong. 2 L divides 6 by the new pressure alone and ignores the starting 2 atmospheres.
• BCorrect. At constant temperature pressure × volume stays the same: 2 × 6 = 12 = 3 × V, so V = 4 L.
• CWrong. 5 L takes away 1 liter for the 1-atmosphere rise; volume changes by ratio (2 × 6 = 3 × V), not in equal steps.
• DWrong. 9 L (6 × 3/2) assumes volume grows with pressure; squeezing a gas harder makes its volume smaller.

Answer: B. One atom gives up electrons and another gains them; the positive and negative ions that result attract each other, as Na⁺ and Cl⁻ do in table salt.

• AWrong. Sharing pairs of electrons makes a covalent bond, the kind that holds a water molecule together.
• BCorrect. One atom gives up electrons and another gains them; the positive and negative ions then attract, as Na⁺ and Cl⁻ do in salt.
• CWrong. Fusing nuclei is nuclear fusion, a nuclear reaction that makes new elements, not a chemical bond.
• DWrong. Atoms releasing electrons into a shared “sea” describes a metallic bond, found in metals such as copper.

Answer: B. Half of 3/4 is 1/2 × 3/4 = 3/8 cup.

• AWrong. 1/4 cup subtracts 1/2 from 3/4. Half of an amount means multiplying by 1/2.
• BCorrect. Half of 3/4 is 1/2 × 3/4 = 3/8 cup.
• CWrong. 1 1/4 cups adds 1/2 to 3/4. That makes more sugar, not less.
• DWrong. 1 1/2 cups divides by 1/2, which doubles the recipe instead of halving it.

Answer: C. 45 ÷ 3 = 15 copies a minute, and 15 × 10 = 150 copies.

• AWrong. 15 is the number of copies in 1 minute. It still has to be multiplied by 10.
• BWrong. 135 multiplies 45 by 3. The 45 copies take 3 minutes, so divide by 3 to get the rate.
• CCorrect. 45 ÷ 3 = 15 copies a minute, and 15 × 10 = 150 copies.
• DWrong. 450 treats 45 as the copies made each minute. 45 copies take 3 minutes.

Answer: C. 15% of $48 is 0.15 × 48 = $7.20. $48 + $7.20 = $55.20.

• AWrong. $7.20 is the tip alone. It still has to be added to the $48 bill.
• BWrong. $48.15 adds 15 cents. A 15% tip is 15 cents for each dollar, which is $7.20 here.
• CCorrect. 15% of $48 is 0.15 × 48 = $7.20. $48 + $7.20 = $55.20.
• DWrong. $63.00 adds $15 instead of 15% of $48.

Answer: D. 48 ÷ 60 = 4/5 = 0.80, which is 80%.

• AWrong. 12% uses the 12 games lost as the percent.
• BWrong. 20% is the percent of games the team lost.
• CWrong. 48% uses the number of wins as the percent. 48 must be divided by 60.
• DCorrect. 48 ÷ 60 = 4/5 = 0.80, which is 80%.

Answer: B. 7:45 a.m. to 4:15 p.m. is 8 1/2 hours. Taking off the 1/2-hour lunch leaves 8 paid hours.

• AWrong. 3 subtracts 4:15 from 7:45 as if both were the same half of the day. The shift crosses noon.
• BCorrect. 7:45 a.m. to 4:15 p.m. is 8 1/2 hours. Taking off the 1/2-hour lunch leaves 8 paid hours.
• CWrong. 8 1/2 is the whole shift. The 30-minute unpaid lunch must come off.
• DWrong. 9 adds the lunch break instead of subtracting it.

Answer: D. Driving apart, the gap grows by 50 + 60 = 110 miles each hour. 110 × 2 1/2 = 275 miles.

• AWrong. 25 miles uses the difference in speeds, which applies only when both cars go the same direction.
• BWrong. 150 miles is how far the faster car alone travels. The other car's 125 miles must be added.
• CWrong. 220 miles uses 2 hours and leaves out the last half hour.
• DCorrect. Driving apart, the gap grows by 50 + 60 = 110 miles each hour. 110 × 2 1/2 = 275 miles.

Answer: D. An 84 average on 5 tests needs 5 × 84 = 420 points. The first 4 tests total 4 × 82 = 328, so the fifth must be 420 − 328 = 92.

• AWrong. 84 matches the goal average, but the first four tests are below it, so the average would only reach 82.4.
• BWrong. 86 adds the 2-point rise to 84 only once. The fifth test must make up 2 points for each of the 4 earlier tests too.
• CWrong. 90 adds 4 × 2 = 8 to the old average of 82. The 8 extra points go on top of the new average: 84 + 8 = 92.
• DCorrect. An 84 average on 5 tests needs 5 × 84 = 420 points. The first 4 tests total 4 × 82 = 328, so the fifth must be 420 − 328 = 92.

Answer: C. 2 × 25 = 50 boxes. 50 ÷ 6 = 8 with 2 left over, so a ninth pack is needed: 9 packs.

• AWrong. 5 packs hold only 30 boxes. That gives each player 1 box, not 2.
• BWrong. 8 packs hold only 48 boxes, 2 short of the 50 needed. The remainder means one more pack.
• CCorrect. 2 × 25 = 50 boxes. 50 ÷ 6 = 8 with 2 left over, so a ninth pack is needed: 9 packs.
• DWrong. 50 is the number of juice boxes, not the number of packs.

Answer: A. Split 6 ways, each share is $540 ÷ 6 = $90. Split 8 ways, it is $540 ÷ 8 = $67.50. Each first friend saves $90 − $67.50 = $22.50.

• ACorrect. Split 6 ways, each share is $540 ÷ 6 = $90. Split 8 ways, it is $540 ÷ 8 = $67.50. Each first friend saves $90 − $67.50 = $22.50.
• BWrong. $67.50 is the new share for each of the 8 friends, not how much less it is.
• CWrong. $90.00 is the original share. The new $67.50 share must be subtracted from it.
• DWrong. $135.00 is what the 2 new friends pay together. Spread over the first 6 friends, that is $22.50 each.

Answer: B. $49 − $35 = $14 in extra charges, and $14 ÷ $0.10 = 140 texts over the limit. 200 + 140 = 340 texts.

• AWrong. 140 is only the texts over the limit. The first 200 texts must be added.
• BCorrect. $49 − $35 = $14 in extra charges, and $14 ÷ $0.10 = 140 texts over the limit. 200 + 140 = 340 texts.
• CWrong. 490 divides the whole $49 bill by $0.10. The $35 monthly charge is not for texts.
• DWrong. 690 divides the whole bill by $0.10 and then adds 200. The $35 monthly charge must come off first.

Answer: D. 234 × 5 = 1,170 miles a week. 1,170 ÷ 18 = 65 gallons, and 65 × $3.80 = $247.00.

• AWrong. $24.70 is the cost of one 117-mile leg on one day. The round trip is 234 miles, made 5 times.
• BWrong. $49.40 is one day's cost (13 gallons). It still has to be multiplied by 5 days.
• CWrong. $123.50 uses 117 miles a day, half the round trip. The 234 miles already counts both ways.
• DCorrect. 234 × 5 = 1,170 miles a week. 1,170 ÷ 18 = 65 gallons, and 65 × $3.80 = $247.00.

Answer: A. $4.20 ÷ 12 = $0.35 a bottle and $9.60 ÷ 30 = $0.32 a bottle. The 30-pack saves $0.35 − $0.32 = $0.03 a bottle.

• ACorrect. $4.20 ÷ 12 = $0.35 a bottle and $9.60 ÷ 30 = $0.32 a bottle. The 30-pack saves $0.35 − $0.32 = $0.03 a bottle.
• BWrong. $0.32 is the 30-pack's price per bottle. It still has to be compared with the 12-pack's $0.35.
• CWrong. $0.35 is the 12-pack's price per bottle, not the difference.
• DWrong. $5.40 is the difference between the package prices, not the difference per bottle.

Answer: C. 20 × 10 × 4 = 800 cubic feet, and 800 × 7.5 = 6,000 gallons. 6,000 ÷ 10 = 600 minutes, which is 600 ÷ 60 = 10 hours.

• AWrong. 1 1/3 divides 800 cubic feet by 10 gallons a minute. The cubic feet must first be changed to 6,000 gallons.
• BWrong. 2 1/2 leaves out the 4-foot depth, so it fills only 200 cubic feet.
• CCorrect. 20 × 10 × 4 = 800 cubic feet, and 800 × 7.5 = 6,000 gallons. 6,000 ÷ 10 = 600 minutes, which is 600 ÷ 60 = 10 hours.
• DWrong. 600 is the time in minutes. Divide by 60 to get hours.

Answer: B. The tank needs 3/4 × 480 = 360 more gallons. It gains 20 − 8 = 12 gallons a minute, so 360 ÷ 12 = 30 minutes.

• AWrong. 18 divides 360 by 20 and ignores the drain. The tank gains only 12 gallons a minute.
• BCorrect. The tank needs 3/4 × 480 = 360 more gallons. It gains 20 − 8 = 12 gallons a minute, so 360 ÷ 12 = 30 minutes.
• CWrong. 40 fills all 480 gallons. The tank is already one-quarter full, so only 360 gallons are needed.
• DWrong. 45 divides 360 by the drain's 8 gallons a minute instead of the net 12.

Answer: D. Together they paint 1/3 of the building a day, and the first crew paints 1/4. The second crew paints 1/3 − 1/4 = 1/12 a day, so it needs 12 days.

• AWrong. 1 subtracts 3 from 4. Work rates are fractions of the job per day, and those are what subtract.
• BWrong. 3 1/2 averages 3 and 4. Times don't average; subtract the daily rates instead: 1/3 − 1/4 = 1/12.
• CWrong. 7 adds the two times. The second crew's rate is 1/3 − 1/4 of the job a day.
• DCorrect. Together they paint 1/3 of the building a day, and the first crew paints 1/4. The second crew paints 1/3 − 1/4 = 1/12 a day, so it needs 12 days.

Answer: C. Damp means slightly wet, which is what moist means.

• AWrong. Dry means free of water, the opposite of damp.
• BWrong. Dirty means covered with dirt or stains, not wetness.
• CCorrect. Damp and moist both mean slightly wet, like a towel that has not fully dried.
• DWrong. Chilly means somewhat cold. Damp things can feel cool, but chilly is about temperature, not water.

Answer: B. Weary means tired, especially after long effort such as a hard climb.

• AWrong. Lost means unable to find the way; it says nothing about being worn out.
• BCorrect. Weary means worn out and tired, which fits hikers after a long climb.
• CWrong. Hungry means wanting food. Hikers may be hungry, but that is not what weary means.
• DWrong. Cheerful means happy and in good spirits, close to the opposite of the worn-out feeling of weary.

Answer: B. To assist someone is to help them.

• AWrong. To pay is to give money for work or goods.
• BCorrect. Assist means help: the volunteers will give the nurses a hand.
• CWrong. To train is to teach someone a skill. It fits a work setting, but it is not what assist means.
• DWrong. To ignore someone is to pay no attention to them, close to the opposite of assist.

Answer: A. A victory is a win in a game, contest, or battle.

• ACorrect. A victory is a win: success in a game, contest, or fight.
• BWrong. A loss is a defeat, the opposite of a victory.
• CWrong. A match is a game or contest. You can win a victory in a match, but the match is the event itself.
• DWrong. A promise is a statement that you will do something.

Answer: A. Vacant means empty, with no one using or living in it.

• ACorrect. Vacant means empty, like a room or lot with no one in it.
• BWrong. Quiet means making little noise; a full room can be quiet.
• CWrong. Rented means paid for by someone to use. Vacant apartments are often for rent, but vacant means empty.
• DWrong. Occupied means in use or lived in, the opposite of vacant.

Answer: A. To conceal something is to hide it from view.

• ACorrect. Conceal means to hide something or keep it out of sight.
• BWrong. To reveal is to show or make known, the opposite of conceal.
• CWrong. To shrink is to become smaller.
• DWrong. To protect is to keep safe from harm. You might hide something to protect it, but the words mean different things.

Answer: A. An obstacle is something that blocks the way or makes progress harder.

• ACorrect. An obstacle is a barrier: something that stands in the way.
• BWrong. A deadline is a time by which work must be done. It fits a job, but it is a date, not a blocking problem.
• CWrong. A shortcut is a quicker way to get something done, nearly the opposite of an obstacle.
• DWrong. A surprise is something unexpected; it may be good or bad and need not block anything.

Answer: B. Candid means open and honest in what one says, which is what frank means.

• AWrong. Rude means impolite. Candid remarks can sound blunt, but candid is about honesty, not manners.
• BCorrect. Candid and frank both mean speaking openly and honestly.
• CWrong. Cheerful means happy and in good spirits.
• DWrong. Secretive means hiding one's thoughts or plans, the opposite of candid.

Answer: C. Consent is permission or approval.

• AWrong. Funding is money provided for a project. A council may fund a park, but consent means permission, not money.
• BWrong. A refusal is a no, the opposite of consent.
• CCorrect. Consent means approval: agreeing that something may go ahead.
• DWrong. Attention is notice or focus; giving attention does not mean agreeing.

Answer: B. A consequence is a result or effect of an action.

• AWrong. A cause is what makes something happen, the opposite end of a consequence.
• BCorrect. A consequence is a result: what follows from an action.
• CWrong. A promise is a statement that you will do something.
• DWrong. A warning tells of possible trouble ahead. People are often warned about consequences, but a warning is not the result itself.

Answer: A. To scrutinize something is to examine it closely and carefully.

• ACorrect. Scrutinize means to examine closely, looking at every detail.
• BWrong. To approve quickly is to accept something without delay, not to look at it closely.
• CWrong. To ignore completely is to pay no attention at all, the opposite of scrutinize.
• DWrong. To criticize harshly is to find fault severely. Close examination may lead to criticism, but scrutinize means only to look carefully.

Answer: B. Skepticism is doubt about whether something is true or will work.

• AWrong. Anger is a feeling of being upset. People may be angry about a plan without doubting it will work.
• BCorrect. Skepticism means doubt: not being convinced something is true or wise.
• CWrong. Approval is agreement or support, nearly the opposite of skepticism.
• DWrong. Confusion is not understanding something; skeptics may understand a plan well and still doubt it.

Answer: D. To exacerbate a problem is to make it worse.

• AWrong. To cause is to make something happen. The rain added to flooding that was already there; exacerbate means make worse.
• BWrong. To reduce is to make smaller or less, the opposite of exacerbate.
• CWrong. To reveal is to show or make known.
• DCorrect. Exacerbate means to worsen: to make a bad situation worse.

Answer: B. Pragmatic means dealing with things in a practical, realistic way.

• AWrong. Cheerful means happy and in good spirits.
• BCorrect. Pragmatic means practical: focused on what works in real life.
• CWrong. Idealistic means guided by ideals rather than by what is workable, the opposite of pragmatic.
• DWrong. Opinionated means holding strong views and stating them often; it says nothing about being practical.

Answer: B. To rescind a rule, order, or offer is to cancel it or take it back.

• AWrong. To hurry is to move or act quickly.
• BCorrect. Rescind means to cancel: to take back a law, order, or offer.
• CWrong. To enforce is to make sure a rule is obeyed, keeping it in force, the opposite of rescinding it.
• DWrong. To rewrite is to write again in a new way. A revised rule is changed, not cancelled.

Answer: B. The notice exists to announce the weekly Friday cleanout. Labeling and taking dishes home are side details about how to avoid losing food or containers.

• AWrong. This detail is in the notice, but it is only an exception to the Friday cleanout, not a summary of the whole notice.
• BCorrect. The notice is built around one rule: everything in the refrigerator is thrown out every Friday afternoon. The other sentences explain exceptions and how to avoid losing items.
• CWrong. Labeling is optional. The notice says labeled food gets an extra week; it does not require anyone to label food.
• DWrong. The notice never bans lunch boxes. It only says to take them home before Friday if you want to keep them.

Answer: A. The last sentence gives the reason: the kelp keeps sleeping otters from drifting away. The key says the same thing in different words.

• ACorrect. The passage says otters wrap themselves in kelp "so they do not drift away while they sleep."
• BWrong. Hiding is not mentioned anywhere in the passage.
• CWrong. The passage never mentions warmth. This is an outside guess, not the reason given.
• DWrong. The passage says otters use a rock on the chest while eating. Kelp is linked only to resting.

Answer: B. The steps are record the hours, get the supervisor's initials, upload, then payroll review and pay. The supervisor's initials come before the upload.

• AWrong. The passage does not tie the upload to the start of a pay period; the deadline given is Monday at noon.
• BCorrect. The sheet is uploaded "once the sheet is initialed," so the supervisor's initials, a form of sign-off, must come first.
• CWrong. Payroll reviews the hours only after the timesheet has been uploaded.
• DWrong. Pay is added at the very end, after payroll reviews the uploaded sheet.

Answer: B. The third sentence states the consequence: no billing system access until the course is completed. The key says the same thing in other words.

• AWrong. Human Resources is mentioned only as the wrong place to send questions, not as a penalty.
• BCorrect. The memo says anyone who misses the deadline will lose billing system access until the course is done.
• CWrong. The memo never says late employees must restart. It says the course can be paused and resumed.
• DWrong. No extension is mentioned. The memo gives a single deadline of March 31.

Answer: D. Most of the passage explains why cities run hotter than the land around them: their materials, layout, lack of trees, and machines. The other options are single details or distortions.

• AWrong. Air conditioners are listed as one of several heat sources. The passage does not name any single main cause.
• BWrong. White roofs are mentioned as one step some cities take. The passage never calls it the best way.
• CWrong. The passage opens with a city being warmer on a summer afternoon, so the effect is not limited to night.
• DCorrect. The passage names the effect and then explains how pavement, buildings, few trees, and machines all make cities hotter than the countryside.

Answer: C. The order is coagulants, settling, filtering, then disinfecting. Settling in the basin comes directly before the filters.

• AWrong. Delivery to homes is the goal after all the stages, not the step before filtering.
• BWrong. Adding coagulants is the first step. The settling basin comes between it and the filters.
• CCorrect. The water rests in a settling basin while the floc sinks, and the passage says the filters come "next."
• DWrong. Chlorine is added in the final step, after filtering.

Answer: C. After the vote, cars left on those streets overnight will be ticketed. To curtail something is to cut it back or restrict it.

• AWrong. The council did more than study the issue; it voted on a rule that takes effect next month.
• BWrong. This is nearly the opposite. The new rule leads to tickets, so parking is being cut back, not expanded.
• CCorrect. Cars parked overnight will now be ticketed, so the council is limiting, or restricting, overnight parking.
• DWrong. Nothing in the passage is about promoting parking; the rule makes overnight parking harder.

Answer: B. The passage contrasts the old, limited view of gut bacteria with their newly found roles, then adds a caution that the research is young. The key captures both parts.

• AWrong. This is the older view the passage says has changed.
• BCorrect. The passage describes how the old view has changed, lists the new roles found, and ends by cautioning that the research is still early.
• CWrong. The passage says antibiotics are one thing that shifts the gut community. It never says they destroy it permanently.
• DWrong. The passage says the bacteria "may" affect mood and warns that the research is early. Nothing has been proven.

Answer: D. The passage ties ring width to rainfall: wide in wet years, narrow in droughts. Several narrow rings in a row therefore suggest several dry years.

• AWrong. Narrow rings are linked to drought, not to the season the tree was cut. The passage says nothing about cutting dates.
• BWrong. This reverses the passage, which links plenty of rain to wide rings, not narrow ones.
• CWrong. The number of rings, not their width, would show age, and several rings in a row means several years of growth.
• DCorrect. The passage says rings are narrow during droughts, so a series of narrow rings points to several dry years.

Answer: A. The author names a common misunderstanding and then explains what the dates really signal. The purpose is to clarify food date labels.

• ACorrect. The passage opens with a common misunderstanding and then explains what "sell by" and "best if used by" really mean.
• BWrong. This is the mistaken belief the passage corrects. The author says the dates are not safety deadlines.
• CWrong. The passage says makers choose their own wording but never explains how they pick the date.
• DWrong. The author explains what labels mean but never calls for removing them.

Answer: C. Multiples of 4: 4, 8, 12, … Multiples of 6: 6, 12, … The first shared multiple is 12.

• AWrong. 2 is the greatest common factor, not the least common multiple.
• BWrong. 10 adds the numbers (4 + 6).
• CCorrect. 12 is the smallest number that both 4 and 6 divide evenly.
• DWrong. 24 multiplies the numbers; it is a common multiple, but not the least.

Answer: A. √144 = 12 and √25 = 5, so 12 − 5 = 7.

• ACorrect. √144 = 12 and √25 = 5, so the difference is 7.
• BWrong. √119 subtracts under one root sign; √144 − √25 is not √(144 − 25).
• CWrong. 17 adds the roots (12 + 5) instead of subtracting.
• DWrong. 119 subtracts 144 − 25 and never takes the square roots.

Answer: C. Add 6 to both sides: 4x = 24. Divide by 4: x = 6.

• AWrong. 3 subtracts 6 from 18 (4x = 12) instead of adding 6.
• BWrong. 4.5 divides 18 by 4 and ignores the −6.
• CCorrect. Add 6: 4x = 24. Divide by 4: x = 6.
• DWrong. 24 is the value of 4x; the last step, dividing by 4, is missing.

Answer: A. Slope = change in y ÷ change in x = (3 − 1) ÷ (8 − 2) = 2/6 = 1/3.

• ACorrect. (3 − 1) ÷ (8 − 2) = 2/6 = 1/3.
• BWrong. 2 is only the change in y; it must be divided by the change in x.
• CWrong. 3 divides the change in x by the change in y (6 ÷ 2), which is upside down.
• DWrong. 6 is only the change in x.

Answer: C. Divide both sides by 5: x − 2 = 7. Add 2: x = 9.

• AWrong. 5 subtracts 2 from 7 instead of adding 2.
• BWrong. 7 is the value of x − 2; the last step, adding 2, is missing.
• CCorrect. x − 2 = 35 ÷ 5 = 7, so x = 9.
• DWrong. 45 is the value of 5x (5x − 10 = 35); it still has to be divided by 5.

Answer: C. 2(3²) − 3(−2) = 2(9) + 6 = 18 + 6 = 24.

• AWrong. 12 treats −3(−2) as −6; a negative times a negative is +6.
• BWrong. 18 reads a² as 2a (3 × 2 = 6), giving 2(6) + 6.
• CCorrect. 2(3²) − 3(−2) = 18 + 6 = 24.
• DWrong. 42 squares 2a instead of a: (2 × 3)² = 36, then 36 + 6.

Answer: D. Find two numbers that multiply to 6 and add to 5: 2 and 3. So x² + 5x + 6 = (x + 2)(x + 3).

• AWrong. (x + 1)(x + 5) = x² + 6x + 5; it swaps the roles of the 5 and the 6.
• BWrong. (x − 2)(x − 3) = x² − 5x + 6; the middle term has the wrong sign.
• CWrong. (x + 1)(x + 6) = x² + 7x + 6; the product is right but the middle term is 7x.
• DCorrect. 2 × 3 = 6 and 2 + 3 = 5, so the form is (x + 2)(x + 3).

Answer: C. Divide and multiply left to right first: 6 ÷ 3 = 2, then 2 × 2 = 4. Then 18 − 4 = 14.

• AWrong. 2 subtracts first and then divides by 3 × 2: 12 ÷ 6.
• BWrong. 8 subtracts first: (18 − 6) ÷ 3 × 2 = 12 ÷ 3 × 2.
• CCorrect. 6 ÷ 3 × 2 = 4 (left to right), and 18 − 4 = 14.
• DWrong. 17 multiplies before dividing: 6 ÷ (3 × 2) = 1, then 18 − 1.

Answer: D. V = πr²h = π × 3² × 5 = 45π cu in.

• AWrong. 9π is only the base area (π × 3²); it still must be multiplied by the height.
• BWrong. 15π uses r instead of r² (π × 3 × 5).
• CWrong. 30π is 2πrh, the curved surface area, not the volume.
• DCorrect. V = πr²h = π × 9 × 5 = 45π cu in.

Answer: D. The parts total 2 + 3 + 4 = 9, so one part is 180° ÷ 9 = 20°. The largest angle is 4 × 20° = 80°.

• AWrong. 20° is the size of one part, not an angle.
• BWrong. 40° is the smallest angle (2 × 20°).
• CWrong. 60° is the middle angle (3 × 20°).
• DCorrect. One part = 180° ÷ 9 = 20°, so the largest angle is 4 × 20° = 80°.

Answer: D. An odd number times an odd number is odd, so n² is odd, and odd + 1 is even.

• AWrong. 3n is odd × odd, which is odd.
• BWrong. n + 2 is odd + even, which is odd.
• CWrong. 2n is even, so 2n + 1 is always odd.
• DCorrect. n² is odd × odd = odd, and adding 1 makes it even.

Answer: A. The length is 2w + 3, so the perimeter is 2w + 2(2w + 3) = 2w + 4w + 6 = 6w + 6.

• ACorrect. Length = 2w + 3, so P = 2w + 2(2w + 3) = 6w + 6.
• BWrong. 3w + 3 adds one width and one length (w + 2w + 3), which is half the perimeter.
• CWrong. 6w + 3 doubles the w terms but not the 3: 2(2w + 3) = 4w + 6.
• DWrong. 2w² + 3w multiplies width by length, which is the area.

Answer: B. P(first red) = 4/6, and then P(second red) = 3/5. So P = 4/6 × 3/5 = 12/30 = 2/5.

• AWrong. 1/3 lowers the red count to 3 but keeps 6 pens in the box: 4/6 × 3/6.
• BCorrect. 4/6 × 3/5 = 12/30 = 2/5.
• CWrong. 4/9 draws with replacement: 4/6 × 4/6.
• DWrong. 2/3 is the chance for the first pen only.

Answer: B. πr² = 36π, so r = 6. Circumference = 2πr = 2π × 6 = 12π in.

• AWrong. 6π uses πr and forgets to double the radius.
• BCorrect. r² = 36, so r = 6 and C = 2π × 6 = 12π in.
• CWrong. 18π halves 36π instead of finding the radius first.
• DWrong. 36π repeats the area; area and circumference are different measures.

Answer: D. Add b to both sides: ax = c + b. Divide both sides by a: x = (c + b)/a.

• AWrong. c/a + b divides only c by a; the whole side c + b must be divided.
• BWrong. a(c + b) multiplies by a instead of dividing by a.
• CWrong. (c − b)/a subtracts b instead of adding it to both sides.
• DCorrect. Add b (ax = c + b), then divide by a: x = (c + b)/a.

Answer: A. By Ohm's law, I = V ÷ R = 6 ÷ 2 = 3 A.

• ACorrect. I = V ÷ R = 6 ÷ 2 = 3 A.
• BWrong. 4 A subtracts the resistance from the voltage (6 − 2), which is not Ohm's law.
• CWrong. 8 A adds the voltage and resistance (6 + 2).
• DWrong. 12 A multiplies volts by ohms (6 × 2); that product would be a voltage, not a current.

Answer: A. An ammeter measures current in amperes.

• ACorrect. An ammeter measures current in amperes; it is connected in series with the load.
• BWrong. An ohmmeter measures resistance.
• CWrong. A voltmeter measures voltage, the potential difference between two points.
• DWrong. A wattmeter measures power in watts.

Answer: A. A contact arm hinged at one terminal and angled away from the other is an open switch.

• ACorrect. A contact arm lifted away from the second terminal is an open single-pole switch.
• BWrong. A fuse is drawn as an S-shaped line or a small rectangle joining two leads.
• CWrong. A lamp is drawn as a circle with an X inside.
• DWrong. A diode is drawn as a triangle pointing at a bar.

Answer: C. A motor uses magnetic forces on current-carrying coils to produce rotation, which is mechanical energy.

• AWrong. Storing electrical energy as chemical energy is what happens when a battery is charged.
• BWrong. Changing electrical energy into light is the job of a lamp or LED.
• CCorrect. A motor turns electrical energy into motion, which is mechanical energy.
• DWrong. Changing electrical energy mainly into heat is the job of a heater or toaster element.

Answer: C. Bare or green wires are equipment grounds. Black or red is normally hot, and white is neutral.

• AWrong. The hot wire is normally black or red.
• BWrong. The neutral wire is normally white or gray.
• CCorrect. Bare copper or green insulation marks the equipment ground wire, a safety path for fault current.
• DWrong. A switched wire carries hot current from a switch to a light and is normally black or red.

Answer: B. R = V ÷ I = 120 ÷ 10 = 12 Ω.

• AWrong. 0.083 Ω divides the current by the voltage (10 ÷ 120), which is upside down.
• BCorrect. R = V ÷ I = 120 ÷ 10 = 12 Ω.
• CWrong. 110 Ω subtracts the current from the voltage (120 − 10).
• DWrong. 1,200 Ω multiplies volts by amps; that product is the power in watts, not the resistance.

Answer: A. Since P = V × I, I = P ÷ V = 60 ÷ 120 = 0.5 A.

• ACorrect. I = P ÷ V = 60 ÷ 120 = 0.5 A.
• BWrong. 2 A divides the voltage by the power (120 ÷ 60), which is upside down.
• CWrong. 180 A adds the watts and volts (60 + 120).
• DWrong. 7,200 A multiplies the watts by the volts instead of dividing.

Answer: A. Two equal parallel plates separated by a gap is the capacitor symbol. A capacitor stores electric charge, holding energy in the electric field between its plates.

• ACorrect. The symbol is a capacitor, which stores charge on two plates separated by an insulator.
• BWrong. Allowing current one way is a diode, drawn as a triangle pointing at a bar.
• CWrong. Changing AC voltage is a transformer, drawn as two coils beside a core.
• DWrong. Opening on overload is a fuse or circuit breaker, which has a different symbol.

Answer: B. 1,500 W = 1.5 kW, and 1.5 kW × 4 h = 6 kWh.

• AWrong. 1.5 is the power in kilowatts; it leaves out the 4 hours.
• BCorrect. Energy = power × time = 1.5 kW × 4 h = 6 kWh.
• CWrong. 60 kWh divides 6,000 Wh by 100 instead of 1,000.
• DWrong. 6,000 is the energy in watt-hours, not kilowatt-hours.

Answer: A. A diode conducts when forward-biased and blocks current in the reverse direction, which is why diodes are used to change AC into DC.

• ACorrect. A diode conducts in the forward direction and blocks current in the reverse direction.
• BWrong. Conducting equally both ways describes a resistor or a plain wire, not a diode.
• CWrong. A diode conducts forward DC as well; it is not limited to AC sources.
• DWrong. Storing charge is what a capacitor does; a diode stores no charge before conducting.

Answer: D. Total resistance is 3 + 9 = 12 Ω, so I = 12 ÷ 12 = 1 A. The voltage across R2 is 1 × 9 = 9 V.

• AWrong. 3 V is the voltage across R1 (1 A × 3 Ω), not R2.
• BWrong. 4 V divides 12 V by R1 alone (12 ÷ 3); that is a current calculation, not the drop across R2.
• CWrong. 6 V assumes the voltage splits evenly, but the larger resistor takes the larger share.
• DCorrect. I = 12 ÷ (3 + 9) = 1 A, and V across R2 = 1 A × 9 Ω = 9 V.

Answer: B. A transformer works by induction, which needs a changing magnetic field. Steady DC makes a constant field, so no voltage is induced in the secondary.

• AWrong. DC of any voltage flows through a coil; the problem is that its field does not change.
• BCorrect. Induction needs a changing magnetic field; steady DC makes a constant field, so the secondary gets no voltage.
• CWrong. DC spreads through the whole wire; crowding toward the surface is a high-frequency AC effect.
• DWrong. The core carries magnetic flux, not current; the coil wire carries the DC.

Answer: C. R2 and R3 in parallel: (6 × 12) ÷ (6 + 12) = 4 Ω. Total = 4 + 4 = 8 Ω, so I = 24 ÷ 8 = 3 A.

• AWrong. 1.1 A treats all three resistors as series (24 ÷ 22), but R2 and R3 are in parallel.
• BWrong. 2.4 A uses only R1 and R2 (24 ÷ 10), ignoring the R3 branch.
• CCorrect. R2 ∥ R3 = 4 Ω; adding R1 gives 8 Ω, and 24 ÷ 8 = 3 A.
• DWrong. 6 A divides by only one 4-Ω value (R1 alone or the parallel pair alone) instead of the 8-Ω total.

Answer: C. Peak voltage = RMS × √2 ≈ 120 × 1.414 ≈ 170 V.

• AWrong. 85 V divides by √2 instead of multiplying (120 ÷ 1.414).
• BWrong. 120 V is the RMS value given in the question; the peak is higher.
• CCorrect. Peak = RMS × √2 ≈ 120 × 1.414 ≈ 170 V.
• DWrong. 240 V simply doubles 120; it is the RMS voltage between the two hot legs of a US service, not the peak.

Answer: C. A bipolar transistor has a base, collector, and emitter. A small base current turns on a much larger collector-emitter current.

• AWrong. Anode is the positive terminal of a diode, not a transistor terminal.
• BWrong. Cathode is the negative terminal of a diode, not a transistor terminal.
• CCorrect. The base is the control terminal of a bipolar (NPN or PNP) transistor.
• DWrong. Drain is a terminal of a field-effect transistor (FET), not of an NPN bipolar transistor.

Answer: B. The alternator is belt-driven by the engine and produces electricity to run the car's systems and recharge the battery.

• AWrong. The starter motor cranks the engine to start it; it uses battery power instead of making it.
• BCorrect. The belt-driven alternator makes electricity while the engine runs, powering the car and recharging the battery.
• CWrong. A distributor sends high-voltage pulses to the spark plugs in older engines; it does not charge the battery.
• DWrong. The ignition coil steps battery voltage up to fire the spark plugs; it does not recharge the battery.

Answer: D. With the engine off and the car on level ground, pull the dipstick, wipe it, push it back in, and pull it again. The oil should reach between the low and full marks.

• AWrong. The oil pressure gauge shows pressure, not how much oil is in the pan; pressure can look normal while the level is low.
• BWrong. The radiator holds coolant, not engine oil.
• CWrong. Removing the filter spills oil and shows nothing about the level in the oil pan.
• DCorrect. The dipstick reaches down into the oil pan, and the oil film on it shows the level against the low and full marks.

Answer: C. Springs hold up the car; shock absorbers slow the springs' motion so the body settles quickly after a bump.

• AWrong. The springs carry the weight of the car; shock absorbers carry almost none of it.
• BWrong. Wheel alignment is set by adjusting the tie rods and suspension arms, not by the shocks.
• CCorrect. Shock absorbers slow the up-and-down motion of the springs, so the body settles quickly after a bump instead of bouncing.
• DWrong. Engine vibration is soaked up by the rubber engine mounts.

Answer: C. The catalytic converter uses metals such as platinum to turn carbon monoxide, unburned fuel, and nitrogen oxides into less harmful gases. Quieting the exhaust is the muffler’s job, and an oxygen sensor measures oxygen.

• AWrong. Quieting exhaust noise is the job of the muffler.
• BWrong. A catalytic converter runs very hot while it works; it does not cool the exhaust.
• CCorrect. Precious metals inside the converter turn carbon monoxide, unburned fuel, and nitrogen oxides into less harmful gases.
• DWrong. An oxygen sensor measures the oxygen in the exhaust; the converter treats the gases.

Answer: D. In a turn, the outside wheel travels farther than the inside wheel. The differential lets them turn at different speeds while both receive power.

• AWrong. The transmission changes the gear ratio for speed and pulling power; it does not split power between the left and right wheels.
• BWrong. The clutch connects and disconnects the engine and the transmission.
• CWrong. A universal joint lets the driveshaft work at an angle as the suspension moves; it does not let the wheels turn at different speeds.
• DCorrect. In a turn the outside wheel travels farther, and the differential’s gears let it turn faster than the inside wheel while both still get power.

Answer: A. The pinion on the steering shaft turns and slides the toothed rack left or right, which pushes the tie rods and steers the wheels. Letting wheels turn at different speeds is the differential’s job.

• ACorrect. The pinion on the steering shaft turns and slides the toothed rack sideways, which pushes the tie rods and steers the wheels.
• BWrong. Letting the wheels turn at different speeds in a corner is the job of the differential.
• CWrong. Camber is set by the suspension’s control arms and struts, not by the steering gear.
• DWrong. Road shock is soaked up mainly by the tires, springs, and shock absorbers.

Answer: B. A diesel squeezes air so tightly that it becomes hot enough to ignite the fuel sprayed into it. Glow plugs only help a cold engine start.

• AWrong. Diesel engines have no spark plugs; ignition comes from the heat of compression.
• BCorrect. Compressing air raises its temperature above the fuel’s ignition point, so the injected diesel fuel lights on its own.
• CWrong. Glow plugs only preheat the cylinders for a cold start; once the engine runs, compression heat does the igniting.
• DWrong. Exhaust valves get hot, but they are not an ignition source; ignition from them would be uncontrolled.

Answer: B. The first number with W is the cold (winter) viscosity rating; a lower number flows better when cold. The 30 is the rating at operating temperature.

• AWrong. The W does not mean weight; both numbers are viscosity grades, not a measure of density.
• BCorrect. The number with the W is the cold (winter) viscosity grade; a lower number means the oil flows better when cold.
• CWrong. Anti-wear additives are listed in the oil’s service rating, not shown by the W.
• DWrong. Resistance to water is not part of the viscosity grade.

Answer: C. Compression ratio = total volume ÷ compressed volume = 550 ÷ 50 = 11:1. Using the swept volume (500 ÷ 50) gives 10:1; adding the 50 cc again (600 ÷ 50) gives 12:1.

• AWrong. 9:1 comes from subtracting 50 cc twice, (550 − 100) ÷ 50; the ratio uses the full cylinder volume.
• BWrong. 10:1 uses the swept volume (550 − 50 = 500) instead of the total volume at bottom dead center.
• CCorrect. Compression ratio = volume at bottom dead center ÷ volume at top dead center = 550 ÷ 50 = 11:1.
• DWrong. 12:1 adds the 50 cc chamber a second time (600 ÷ 50); the 550 cc already includes it.

Answer: D. Oil temporarily seals the gap around worn piston rings, so the pressure comes up. A leak at a valve or head gasket is not sealed by oil, so that reading would stay low.

• AWrong. Ignition does not affect a compression test; the engine is only cranked, and nothing needs to fire.
• BWrong. A burned valve leaks at its seat in the head, which oil in the cylinder cannot seal, so the reading would stay low.
• CWrong. A head gasket leak is not sealed by oil either; a leak between cylinders usually shows as two side-by-side cylinders reading low.
• DCorrect. A little oil seals the gap around worn rings for a moment, so a big jump in the reading points to the rings.

Answer: C. A bolt passes through the parts and is held by a nut threaded onto its end. Wood screws cut their own threads into the wood.

• AWrong. A wood screw cuts its own threads into the wood and needs no nut.
• BWrong. A common nail is driven with a hammer and held by friction.
• CCorrect. A bolt passes through the parts and is held by a nut threaded onto its end.
• DWrong. A staple is driven into the material and has no threads.

Answer: A. A grinder throws sparks and metal chips toward the operator, so safety glasses or a face shield are essential.

• ACorrect. A grinder throws sparks and bits of metal toward the operator, so safety glasses or a face shield come first.
• BWrong. Knee pads protect the knees when kneeling; they do nothing at a bench grinder.
• CWrong. A hard hat guards against falling objects overhead, not flying sparks.
• DWrong. Rubber gloves protect against chemicals; gloves can even be caught by a spinning wheel.

Answer: A. This is a wing nut. Its two flat wings let you turn it with your fingers, so it is used where parts are taken apart often without tools.

• ACorrect. The two wings give your fingers something to grip, so no wrench is needed.
• BWrong. Nuts are threaded onto bolts, not hammered; hammering would ruin the threads.
• CWrong. Weld nuts have small tabs or bumps for welding and no wings.
• DWrong. A castle nut has slots on top for a cotter pin; a wing nut has none.

Answer: B. A 2 × 4 is named by its rough size before drying and planing. The finished board measures 1½ in × 3½ in.

• AWrong. 1¼ × 3¼ in is too small; drying and planing removes ½ in from each nominal size.
• BCorrect. A 2 × 4 is named by its rough size; after drying and planing it measures 1½ in × 3½ in.
• CWrong. 1¾ × 3¾ in removes only ¼ in from each nominal size.
• DWrong. 2 × 4 is the nominal (name) size, not the finished size of dry, planed lumber.

Answer: A. Disconnecting power guarantees the saw cannot start while your hands are near the blade.

• ACorrect. Cutting the power means the saw cannot start while your hands are near the blade.
• BWrong. Running the saw while preparing to handle the blade is exactly the danger to avoid.
• CWrong. The guard spring must stay working so the guard snaps back over the blade; loosening it is unsafe.
• DWrong. Locking the trigger on would keep the blade spinning while your hands are near it.

Answer: A. Toothed jaws, a hook jaw set by a knurled adjusting nut, and a long handle mark a pipe wrench. Its teeth bite into round pipe as the handle is pulled.

• ACorrect. The toothed hook and heel jaws, moved by a knurled nut, are made to grip round pipe.
• BWrong. An adjustable wrench has smooth, flat jaws for nuts and bolts, with a small worm screw in the head.
• CWrong. A box-end wrench has a closed ring that surrounds a nut and no moving jaw.
• DWrong. A torque wrench turns a socket and shows or clicks at a set tightness; it has no jaws.

Answer: C. A six-point box end surrounds the nut and contacts all six flats. Open-end and adjustable wrenches grip only two flats and slip more easily.

• AWrong. An open-end wrench grips only two flats, so it can slip and round the corners under high force.
• BWrong. An adjustable wrench grips two flats, and its movable jaw can loosen and slip.
• CCorrect. A six-point box end surrounds the nut and pushes on all six flats, so it spreads the force and holds without slipping.
• DWrong. A pipe wrench has toothed jaws for round pipe; the teeth chew up the corners of a nut.

Answer: C. A flat, paddle-shaped blade with a sharp center point on a six-sided shank is a spade bit. It bores large holes in wood quickly.

• AWrong. An auger bit has a spiral body with a threaded screw tip that pulls the bit into the wood.
• BWrong. A masonry bit has a spiral body with a flat carbide tip brazed across its end.
• CCorrect. The flat paddle with a center point and two small side spurs is a spade bit.
• DWrong. A twist bit is a round rod with spiral grooves and a cone-shaped point.

Answer: C. Add the thimble to the sleeve: 0.250 + (12 × 0.001) = 0.250 + 0.012 = 0.262 in. Counting each division as 0.010 in gives 0.370 in.

• AWrong. 0.238 in subtracts the thimble reading from the sleeve instead of adding it.
• BWrong. 0.2512 in counts each thimble division as 0.0001 in instead of 0.001 in.
• CCorrect. Add the thimble to the sleeve: 0.250 + 12 × 0.001 = 0.250 + 0.012 = 0.262 in.
• DWrong. 0.370 in counts each thimble division as 0.010 in (0.250 + 0.120).

Answer: D. Chisel-shaped teeth are the mark of a ripsaw, which chips wood out along the grain. A crosscut saw’s teeth are filed at an angle into knife points that slice across the grain.

• AWrong. Curves are cut with a coping saw or a jigsaw, whose narrow blades can turn.
• BWrong. Metal is cut with a hacksaw’s fine, hardened teeth.
• CWrong. Crosscutting needs teeth filed at a bevel into knife-like points that slice the wood fibers; chisel teeth would tear them.
• DCorrect. Chisel-like teeth chip out wood along the grain, which is what a ripsaw is made for.

Answer: B. Two gears that mesh directly always turn in opposite directions, so B turns counterclockwise.

• AWrong. Meshed teeth push each other in opposite directions, so B cannot turn the same way as A.
• BCorrect. Two gears that mesh directly always turn in opposite directions. A turns clockwise, so B turns counterclockwise.
• CWrong. A gear driven by a gear that keeps turning one way also keeps turning one way; nothing here reverses it.
• DWrong. The teeth are meshed, so when A turns it must push B around.

Answer: A. An object is most stable when its center of gravity is low and its base is wide. Block A is short and wide, so it must be tilted the farthest before it tips.

• ACorrect. Block A has the widest base and the lowest center of gravity, so it must tilt farthest before it tips.
• BWrong. Block B is tall and narrow: its center of gravity is high over a small base, so a small tilt tips it.
• CWrong. Block C is fairly stable, but its center of gravity is higher and its base narrower than block A’s.
• DWrong. Block D carries most of its weight at the top on a narrow post, so it tips most easily.

Answer: D. Every ramp lifts the barrel the same height, so the work is the same. The longest, least steep ramp spreads that work over the greatest distance, so it needs the least force.

• AWrong. Ramp A is the shortest and steepest, so it needs the most force.
• BWrong. Ramp B is longer than A but still steeper than C and D.
• CWrong. Ramp C is less steep than A and B, but ramp D is longer still.
• DCorrect. The same work spread over the longest distance needs the least force, so ramp D is easiest.

Answer: C. Weight × distance must be equal on both sides: 60 × 6 = 360 ft·lb, so the 90-lb child sits 360 ÷ 90 = 4 ft from the pivot, at point C.

• AWrong. Point A is 2 ft out: 90 × 2 = 180 ft·lb, only half of the 360 ft·lb on the other side.
• BWrong. Point B (3 ft) halves the distance, which balances only a child twice as heavy (120 lb); 90 × 3 = 270 ft·lb.
• CCorrect. 60 × 6 = 360 ft·lb on the left, and 360 ÷ 90 = 4 ft, which is point C.
• DWrong. Point D is the same 6-ft distance, which balances only equal weights; 90 × 6 = 540 ft·lb would tip the seesaw.

Answer: D. Stretch is proportional to force (Hooke’s law). The spring stretches 2 in per 10 lb, or 0.2 in per pound: 25 × 0.2 = 5 in.

• AWrong. 2 in is the stretch for 10 lb; a heavier weight stretches the spring farther.
• BWrong. 2.5 in is only the ratio of the weights (25 ÷ 10), not multiplied by the 2 in of stretch per 10 lb.
• CWrong. 4 in doubles the stretch, as if 25 lb were twice 10 lb; it is 2.5 times as much.
• DCorrect. Stretch is proportional to force: 0.2 in per lb × 25 lb = 5 in.

Answer: A. The follower rests on the edge of the cam. It is highest when the lobe (3 in from the shaft) is under it and lowest on the round part (2 in from the shaft), so it moves 3 − 2 = 1 in.

• ACorrect. The follower moves by the difference between the cam’s longest and shortest distance from the shaft: 3 − 2 = 1 in.
• BWrong. 2 in is the round part’s distance from the shaft center, not how far the follower moves.
• CWrong. 3 in is the lobe’s distance from the shaft center; the follower never drops all the way to the shaft.
• DWrong. 5 in adds the two distances, which is the cam’s full height, not the change in the follower’s position.

Answer: A. Effort × effort arm = load × load arm: F × 6 = 120 × 2 = 240, so F = 40 lb.

• ACorrect. F × 6 = 120 × 2 = 240, so F = 40 lb.
• BWrong. 60 lb just halves the load and ignores the actual arm lengths (2 ft and 6 ft).
• CWrong. 120 lb assumes you must push as hard as the load; the effort arm is 3 times the load arm.
• DWrong. 360 lb applies the arm ratio backwards (120 × 6 ÷ 2), as if the effort were on the short arm.

Answer: B. Four rope strands hold up the lower (movable) block, so the mechanical advantage is 4: 240 ÷ 4 = 60 lb. The free end pulled downward does not support the load.

• AWrong. 48 lb divides by 5, counting the free end pulled downward, which does not hold up the lower block.
• BCorrect. Four strands support the lower block, so the mechanical advantage is 4 and F = 240 ÷ 4 = 60 lb.
• CWrong. 80 lb divides by 3, missing one of the four strands that hold up the lower block.
• DWrong. 120 lb divides by 2, as if the system had only one movable pulley.

Answer: C. Gravity pulls both balls down the same way, and neither starts with any downward speed, so both fall the same height in the same time. B’s sideways speed only carries it farther from the wall.

• AWrong. A’s path is shorter, but both balls fall the same height with the same downward acceleration, so A does not land sooner.
• BWrong. B’s sideways speed does not pull it down any faster; its fall is the same as A’s.
• CCorrect. Both balls start with no downward speed and fall the same height under the same gravity, so they land together.
• DWrong. B’s speed changes how far from the wall it lands, not how long it takes to fall.

Answer: B. The same number of teeth pass every mesh each minute, so B (an idler) does not change the overall ratio: 90 × 10 = 15 × C, and C turns at 60 rpm.

• AWrong. 30 rpm is the speed of gear B (90 × 10 ÷ 30), not gear C.
• BCorrect. B is an idler, so the overall ratio is A to C: 90 × 10 ÷ 15 = 60 rpm.
• CWrong. 90 rpm assumes C matches A because B is an idler, but C has more teeth than A, so it turns slower.
• DWrong. 135 rpm applies the A-to-C ratio backwards (90 × 15 ÷ 10); the gear with more teeth turns slower.

Answer: C. A floating object weighs the same as the water it displaces. The block displaces 2 ft³ of water, which weighs 2 × 62.4 = 124.8 lb.

• AWrong. 41.6 lb multiplies 62.4 by the fraction 2/3 instead of by the 2 ft³ of water the block displaces.
• BWrong. 62.4 lb is the weight of 1 ft³ of water, the part of the block above the surface, which displaces nothing.
• CCorrect. A floating object weighs as much as the water it displaces: 2 ft³ × 62.4 = 124.8 lb.
• DWrong. 187.2 lb uses the whole 3 ft³; only the part under water displaces water.

Answer: C. The support closer to the load carries more. Taking turning effects about B: A × 12 = 300 × 8, so A = 200 lb (and B carries 100 lb).

• AWrong. 100 lb is support B’s share; the support nearer the load carries more.
• BWrong. 150 lb splits the load evenly, which is right only for a centered load.
• CCorrect. Taking turning effects about B: A × 12 = 300 × 8, so A = 200 lb.
• DWrong. 300 lb gives the whole load to A, but support B also helps hold it.

Answer: D. The same volume of water passes each point every second, so speed × area stays constant. Halving the diameter cuts the area to 1/4, so the speed rises 4 times: 3 × 4 = 12 ft/s.

• AWrong. 0.75 ft/s applies the area ratio backwards; water speeds up where the pipe narrows.
• BWrong. 1.5 ft/s applies the diameter ratio backwards; the water must speed up, not slow down.
• CWrong. 6 ft/s uses the diameter ratio (2 times), but flow depends on area, which shrinks 4 times.
• DCorrect. Half the diameter means 1/4 the area, so the water moves 4 times as fast: 3 × 4 = 12 ft/s.

Answer: C. A 30-lb push is less than the 40 lb needed to start the crate, so it stays at rest. Static friction pushes back just as hard as the push, 30 lb, so the forces balance.

• AWrong. The crate is pushed but does not move, so friction must be pushing back; it is not zero.
• BWrong. 25 lb is sliding friction, which applies only once the crate moves; this push is too weak to start it.
• CCorrect. Static friction matches the push up to its 40-lb limit, so it equals the 30-lb push.
• DWrong. 40 lb is the most static friction can supply; a 40-lb friction force against a 30-lb push would shove the crate backward.

Answer: A. Heating a ring evenly enlarges every dimension by the same fraction, including the hole, like an enlarged photograph. The hole gets larger, which is why heating a ring lets it slide over a shaft.

• ACorrect. Even heating enlarges every dimension of the ring by the same fraction, so the hole grows and the ring can slide on.
• BWrong. The metal does not swell into the hole; the whole ring, hole included, scales up like an enlarged photo.
• CWrong. The inner edge expands along with the outer edge, so the hole cannot stay the same.
• DWrong. Heating the shaft would make the shaft bigger and harder to fit; the ring’s hole grows on its own.

Answer: A. Point A is at the middle of a side of the square 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 middle of a side of the square (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 leaves the square at the center, but A is at the middle of a side.
• CWrong. The line leaves the square at a corner, but A is at the middle of a side.
• DWrong. The line meets the circle at the edge, but B is at the center.

Answer: B. The loose pieces are three rectangles 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 a right triangle and a trapezoid, but the box holds three rectangles.
• BCorrect. This square is cut into three rectangles: exactly the pieces in the box, at the same size.
• CWrong. This square is cut into a right triangle and a five-sided piece, but the box holds three rectangles.
• DWrong. This square is cut into two rectangles, but the box holds three rectangles.

Answer: B. Point A is at a corner of the triangle 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 meets the square at the middle of a side, but B is at a corner.
• BCorrect. The line joins a corner of the triangle (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 triangle at the middle of a side, but A is at a corner; and the line meets the square at the center, but B is at a corner.
• DWrong. The line leaves the triangle at the middle of a side, but A is at a corner.

Answer: D. Point A is at a corner of the square 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 square at the middle of a side, but A is at a corner.
• BWrong. The line meets the circle at the center, but B is at the edge.
• CWrong. The line leaves the square at the center, but A is at a corner.
• DCorrect. The line joins a corner of the square (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: A. 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.

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

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

Answer: A. Point A is at the middle of the shortest side of the rectangle and point B is at the middle of the shortest 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.

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

Answer: A. Point A is at the edge of the circle 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 edge of the circle (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 leaves the circle at the center, but A is at the edge; and the line meets the circle at the edge, but B is at the center.
• CWrong. The line leaves the circle at the center, but A is at the edge.
• DWrong. The line meets the circle at the edge, but B is at the center.

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

Answer: A. The loose pieces are two thirds and two 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 two thirds and two sixths of a circle: exactly the pieces in the box, at the same size.
• BWrong. This circle is cut into four quarters of a circle, but the box holds two thirds and two sixths of a circle.
• CWrong. This circle is cut into a half, a third, and a sixth of a circle, but the box holds two thirds and two sixths of a circle.
• DWrong. This circle is cut into three thirds of a circle, but the box holds two thirds and two sixths of a circle.

Answer: D. The loose pieces are two squares 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 two right triangles, but the box holds two squares.
• BWrong. This rectangle is cut into a right triangle and a trapezoid, but the box holds two squares.
• CWrong. This rectangle is cut into two trapezoids, but the box holds two squares.
• DCorrect. This rectangle is cut into two squares: exactly the pieces in the box, at the same size.

Answer: A. Point A is at the widest corner of the parallelogram and point B is at the middle of a side of the pentagon. 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 parallelogram (A) to the middle of a side of the pentagon (B), exactly as marked. The shapes are only turned, which doesn't change where the line attaches.
• BWrong. The line leaves the parallelogram at the middle of the longest side, but A is at the widest corner.
• CWrong. The line leaves the parallelogram at the middle of the shortest side, but A is at the widest corner.
• DWrong. The line leaves the parallelogram at the sharpest corner, but A is at the widest corner.

Answer: B. 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 two squares, but the box holds a right triangle and a trapezoid.
• BCorrect. This rectangle is cut into a right triangle and a trapezoid: exactly the pieces in the box, at the same size.
• CWrong. This rectangle is cut into two trapezoids, but the box holds a right triangle and a trapezoid.
• DWrong. This rectangle is cut into two right triangles, but the box holds a right triangle and a trapezoid.

Answer: B. The loose pieces are a rectangle and two squares 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 a rectangle and two right triangles, but the box holds a rectangle and two squares.
• BCorrect. This square is cut into a rectangle and two squares: exactly the pieces in the box, at the same size.
• CWrong. This square is cut into three rectangles, but the box holds a rectangle and two squares.
• DWrong. This square is cut into a right triangle and a five-sided piece, but the box holds a rectangle and two squares.

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