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ASVAB practice questions

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Question 1General Science (GS)

Which organelle is the main site of ATP production in a eukaryotic cell?

  1. Lysosome
  2. Golgi apparatus
  3. Ribosome
  4. Mitochondrion Correct answer.

Explanation

Mitochondria carry out aerobic respiration, using oxygen to release energy from glucose and store it in ATP molecules. Cells with high energy demands, such as muscle cells, contain large numbers of mitochondria.

Question 2General Science (GS)

Which planet is often called the Red Planet because iron oxide dust on its surface gives it a reddish color?

  1. Jupiter
  2. Mercury
  3. Venus
  4. Mars Correct answer.

Explanation

Mars appears reddish because its surface rocks and dust contain iron oxide, or rust. It is the fourth planet from the Sun and is smaller than Earth.

Question 3General Science (GS)

Which process changes a liquid into a gas throughout the entire liquid, not just at its surface?

  1. Condensation
  2. Boiling Correct answer.
  3. Sublimation
  4. Freezing

Explanation

Boiling occurs when a liquid's vapor pressure equals the surrounding pressure, so bubbles of vapor form throughout the liquid and rise to the surface. Evaporation, by contrast, happens only at the surface and at temperatures below the boiling point.

Question 4General Science (GS)

Which is the largest organ of the human body?

  1. Liver
  2. Lungs
  3. Skin Correct answer.
  4. Brain

Explanation

The skin is the body's largest organ by both surface area and mass. It serves as a barrier against pathogens, helps regulate temperature, and contains sensory receptors.

Question 5General Science (GS)

In a food chain, which organisms capture sunlight and convert it into chemical energy?

  1. Producers Correct answer.
  2. Primary consumers
  3. Decomposers
  4. Secondary consumers

Explanation

Producers, such as green plants and algae, use photosynthesis to convert light energy into chemical energy stored in sugars. All other feeding levels depend on the energy the producers capture.

Question 6General Science (GS)

Which mineral is the hardest on the Mohs hardness scale?

  1. Diamond Correct answer.
  2. Topaz
  3. Quartz
  4. Corundum

Explanation

The Mohs scale ranks minerals by their ability to scratch one another, from talc at 1 to diamond at 10. Diamond is the hardest naturally occurring mineral because of the strong covalent bonding of its carbon atoms.

Question 7General Science (GS)

What is the chemical symbol for sodium?

  1. Sd
  2. Na Correct answer.
  3. So
  4. N

Explanation

Chemical symbols come from element names, often from Latin or other historical sources. Sodium's symbol is Na, from the Latin word natrium.

Question 8General Science (GS)

Which of these materials is a good conductor of electricity?

  1. Copper Correct answer.
  2. Glass
  3. Rubber
  4. Dry wood

Explanation

Metals such as copper conduct electricity well because their outer electrons are loosely held and can move freely through the material. Rubber, glass, and dry wood hold their electrons tightly and act as insulators.

Question 9General Science (GS)

Which two substances do plants take in to carry out photosynthesis?

  1. Carbon dioxide and water Correct answer.
  2. Carbon dioxide and oxygen
  3. Oxygen and glucose
  4. Nitrogen and water

Explanation

Using light energy trapped by chlorophyll, plants combine carbon dioxide from the air with water from the soil to produce glucose, releasing oxygen as a byproduct. The glucose stores the captured energy.

Question 10General Science (GS)

A rocket moves forward by expelling hot gases backward. Which principle best explains this motion?

  1. Archimedes' principle
  2. Newton's third law Correct answer.
  3. Newton's first law
  4. Newton's law of universal gravitation

Explanation

Newton's third law states that every action has an equal and opposite reaction. The rocket pushes gas backward, and the gas pushes the rocket forward with an equal force.

Question 11General Science (GS)

Which statement describes a solution with a pH of 3?

  1. It has equal concentrations of hydrogen and hydroxide ions.
  2. It is basic and contains excess hydroxide ions.
  3. It is acidic and has excess hydrogen ions. Correct answer.
  4. It is neutral.

Explanation

The pH scale runs from 0 to 14, with values below 7 indicating acidic solutions. A pH of 3 means the solution has a relatively high concentration of hydrogen ions compared with pure water, which has a pH of 7.

Question 12General Science (GS)

In a DNA molecule, adenine on one strand pairs with which base on the opposite strand?

  1. Thymine Correct answer.
  2. Adenine
  3. Cytosine
  4. Guanine

Explanation

DNA bases pair by complementary shape and hydrogen bonding: adenine pairs with thymine, and guanine pairs with cytosine. This consistent pairing lets one strand serve as a template for copying the other.

Question 13General Science (GS)

Which type of blood vessel carries blood away from the heart?

  1. Capillaries
  2. Lymph vessels
  3. Arteries Correct answer.
  4. Veins

Explanation

Arteries carry blood away from the heart and branch into smaller vessels that lead to capillary beds. Their thick, elastic walls help them withstand the pressure created by each heartbeat.

Question 14General Science (GS)

In which layer of Earth's atmosphere does nearly all weather occur?

  1. Thermosphere
  2. Mesosphere
  3. Stratosphere
  4. Troposphere Correct answer.

Explanation

The troposphere is the lowest layer of the atmosphere and contains most of its water vapor and air. Heating from below creates the vertical mixing and pressure differences that produce clouds, storms, and other weather.

Question 15General Science (GS)

A pad of steel wool is sealed inside a jar of air and allowed to rust completely. The total mass of the sealed jar and its contents will be:

  1. impossible to predict
  2. greater than before rusting
  3. less than before rusting
  4. the same as before rusting Correct answer.

Explanation

In a closed system, matter is conserved during a chemical change; atoms are only rearranged into new compounds. The iron combines with oxygen already present inside the jar, so no mass enters or leaves.

Question 16General Science (GS)

As a roller coaster car rolls down from the top of a hill, most of its stored energy is converted into which form?

  1. Chemical energy
  2. Electrical energy
  3. Kinetic energy Correct answer.
  4. Nuclear energy

Explanation

An object raised above the ground has gravitational potential energy, which decreases as it descends. That stored energy is converted mainly into kinetic energy, so the car speeds up.

Question 17General Science (GS)

Bile, which helps break fats into smaller droplets, is produced by which organ?

  1. Gallbladder
  2. Pancreas
  3. Stomach
  4. Liver Correct answer.

Explanation

The liver produces bile, which is stored and concentrated in the gallbladder before being released into the small intestine. Bile salts emulsify fats, increasing the surface area available to fat-digesting enzymes.

Question 18General Science (GS)

A relationship between two species in which both individuals benefit is called:

  1. parasitism
  2. commensalism
  3. predation
  4. mutualism Correct answer.

Explanation

Mutualism is a symbiotic relationship that benefits both partners, such as bees obtaining nectar while pollinating flowers. Each species gains something that improves its survival or reproduction.

Question 19General Science (GS)

If a sound wave's frequency increases while its speed stays the same, what happens to its wavelength?

  1. It increases.
  2. It doubles.
  3. It decreases. Correct answer.
  4. It stays the same.

Explanation

Wave speed equals frequency multiplied by wavelength. If the speed is fixed and the frequency rises, the wavelength must shrink to keep the product constant.

Question 20General Science (GS)

Which group of elements is chemically unreactive because its atoms have complete outer electron shells?

  1. Noble gases Correct answer.
  2. Alkaline earth metals
  3. Halogens
  4. Alkali metals

Explanation

Noble gases such as helium and neon have full valence shells, so they neither gain nor lose electrons readily. This stable configuration makes them largely inert under ordinary conditions.

Question 21General Science (GS)

New oceanic crust is created along which type of plate boundary?

  1. Subduction zones
  2. Deep-sea trenches
  3. Mid-ocean ridges Correct answer.
  4. Continental interiors

Explanation

Mid-ocean ridges are divergent boundaries where plates pull apart and magma rises to fill the gap. The magma cools to form new seafloor that spreads outward from the ridge.

Question 22General Science (GS)

Water moves across a cell membrane from a region of lower solute concentration to a region of higher solute concentration without the cell using energy. This movement is called:

  1. phagocytosis
  2. active transport
  3. osmosis Correct answer.
  4. facilitated diffusion

Explanation

Osmosis is the diffusion of water through a selectively permeable membrane down its own concentration gradient. Because it follows the gradient, no cellular energy is required.

Question 23General Science (GS)

Water boils at a much higher temperature than hydrogen sulfide (H2S), even though the two molecules have similar shapes. What best explains this?

  1. Water molecules are heavier than hydrogen sulfide molecules.
  2. Hydrogen bonds between water molecules must be broken. Correct answer.
  3. Water contains ionic bonds that are hard to break.
  4. Water molecules have a lower molar mass than hydrogen sulfide molecules.

Explanation

Oxygen is more electronegative than sulfur, so water molecules form strong hydrogen bonds with one another. Boiling requires breaking many of these attractions, which takes considerably more energy.

Question 24General Science (GS)

Two 6-ohm resistors are connected in series across a 12-volt battery. What current flows through the circuit?

  1. 1 A Correct answer.
  2. 12 A
  3. 2 A
  4. 4 A

Explanation

In a series circuit the resistances add, giving a total of 12 ohms. Ohm's law then gives current as voltage divided by resistance, or 12 V divided by 12 ohms, which equals 1 A.

Question 25General Science (GS)

In the reaction 2H2 + O2 -> 2H2O, how many grams of water can be produced from 4.0 g of H2 when oxygen is plentiful?

  1. 36 g Correct answer.
  2. 32 g
  3. 18 g
  4. 4 g

Explanation

Hydrogen has a molar mass of about 2 g/mol, so 4.0 g is 2.0 mol of H2. The balanced equation shows each mole of H2 yields one mole of water, and 2 mol of water at 18 g/mol equals 36 g.

Question 26Arithmetic Reasoning (AR)

What is 15% of 200?

  1. 20
  2. 60
  3. 45
  4. 30 Correct answer.

Explanation

Convert the percent to a decimal by dividing by 100, so 15% = 0.15. Multiplying 0.15 by 200 gives 30.

Question 27Arithmetic Reasoning (AR)

A car travels 180 miles on 6 gallons of gas. What is its rate in miles per gallon?

  1. 30 Correct answer.
  2. 24
  3. 48
  4. 36

Explanation

A unit rate is found by dividing the total distance by the total number of gallons. Here 180 ÷ 6 = 30 miles per gallon.

Question 28Arithmetic Reasoning (AR)

A recipe calls for 3/4 cup of sugar. If you make half the recipe, how much sugar is needed?

  1. 1/4 cup
  2. 3/2 cups
  3. 1/2 cup
  4. 3/8 cup Correct answer.

Explanation

Making half the recipe means multiplying each amount by 1/2. So 3/4 × 1/2 = 3/8 cup.

Question 29Arithmetic Reasoning (AR)

What is the average of 4, 8, 10, and 14?

  1. 8
  2. 9 Correct answer.
  3. 7
  4. 8.5

Explanation

The average is the sum of the values divided by how many values there are. The sum is 4 + 8 + 10 + 14 = 36, and 36 ÷ 4 = 9.

Question 30Arithmetic Reasoning (AR)

A shirt costs $24.50. If you pay with a $30 bill, how much change should you receive?

  1. $6.00
  2. $5.00
  3. $5.50 Correct answer.
  4. $6.50

Explanation

Subtract the cost from the amount paid to find the change. $30.00 − $24.50 = $5.50.

Question 31Arithmetic Reasoning (AR)

A rectangle is 9 meters long and 4 meters wide. What is its perimeter?

  1. 72 m
  2. 36 m
  3. 26 m Correct answer.
  4. 13 m

Explanation

The perimeter of a rectangle is 2 times the length plus 2 times the width. So 2(9) + 2(4) = 18 + 8 = 26 meters.

Question 32Arithmetic Reasoning (AR)

If 3 pounds of apples cost $4.50, how much do 5 pounds cost at the same rate?

  1. $8.50
  2. $7.50 Correct answer.
  3. $6.50
  4. $7.00

Explanation

Find the unit price first: $4.50 ÷ 3 = $1.50 per pound. Then multiply $1.50 by 5 pounds to get $7.50.

Question 33Arithmetic Reasoning (AR)

How many minutes are there in 2.5 hours?

  1. 140
  2. 150 Correct answer.
  3. 125
  4. 120

Explanation

Each hour contains 60 minutes, so multiply the number of hours by 60. 2.5 × 60 = 150 minutes.

Question 34Arithmetic Reasoning (AR)

A jacket regularly priced at $80 is on sale for 25% off. What is the sale price?

  1. $60 Correct answer.
  2. $65
  3. $55
  4. $20

Explanation

The discount is 25% of $80, which is 0.25 × 80 = $20. Subtracting the discount from the original price gives $80 − $20 = $60.

Question 35Arithmetic Reasoning (AR)

A train travels at a steady 60 miles per hour for 2 hours and 15 minutes. How far does it travel?

  1. 150 mi
  2. 120 mi
  3. 135 mi Correct answer.
  4. 180 mi

Explanation

Convert 2 hours 15 minutes to 2.25 hours. Then multiply the speed by the time: 60 × 2.25 = 135 miles.

Question 36Arithmetic Reasoning (AR)

Pipe A can fill a tank in 6 hours, and pipe B can fill the same tank in 3 hours. Working together, how long will they take to fill the tank?

  1. 2 hours Correct answer.
  2. 4.5 hours
  3. 1.5 hours
  4. 9 hours

Explanation

Add the work rates: 1/6 + 1/3 = 1/6 + 2/6 = 1/2 tank per hour. The reciprocal of that combined rate gives 2 hours to fill one tank.

Question 37Arithmetic Reasoning (AR)

The sum of three consecutive integers is 84. What is the largest of the three integers?

  1. 26
  2. 28
  3. 29 Correct answer.
  4. 27

Explanation

Let the integers be n, n + 1, and n + 2. Their sum is 3n + 3 = 84, so 3n = 81 and n = 27. The largest integer is then 29.

Question 38Arithmetic Reasoning (AR)

A sum of $240 is divided between two people in the ratio 3:5. How much does the person with the larger share receive?

  1. $180
  2. $150 Correct answer.
  3. $120
  4. $90

Explanation

The ratio 3:5 has 8 equal parts, so one part is $240 ÷ 8 = $30. The larger share is 5 parts, or 5 × $30 = $150.

Question 39Arithmetic Reasoning (AR)

A product's price rises from $40 to $50. What is the percent increase?

  1. 50%
  2. 25% Correct answer.
  3. 20%
  4. 10%

Explanation

Percent increase equals the change divided by the original amount, times 100. The change is $10, and 10 ÷ 40 × 100 = 25%.

Question 40Arithmetic Reasoning (AR)

A circular garden has a radius of 5 meters. Using 3.14 for pi, what is its area?

  1. 31.4 m²
  2. 78.5 m² Correct answer.
  3. 15.7 m²
  4. 157 m²

Explanation

The area of a circle is found with the formula A = pi × r². With r = 5, r² = 25, so 3.14 × 25 = 78.5 square meters.

Question 41Arithmetic Reasoning (AR)

The average of five numbers is 12. Four of the numbers are 8, 10, 14, and 15. What is the fifth number?

  1. 11
  2. 12
  3. 13 Correct answer.
  4. 15

Explanation

If the average of five numbers is 12, their total is 5 × 12 = 60. The four known numbers add to 47, so the fifth number is 60 − 47 = 13.

Question 42Arithmetic Reasoning (AR)

How much simple interest is earned on $1,200 at an annual rate of 5% for 2 years?

  1. $1,320
  2. $60
  3. $240
  4. $120 Correct answer.

Explanation

Simple interest is principal × rate × time. Here $1,200 × 0.05 × 2 = $120.

Question 43Arithmetic Reasoning (AR)

A solution is 20% acid. How many liters of pure acid are in 15 liters of the solution?

  1. 5 L
  2. 12 L
  3. 3 L Correct answer.
  4. 2 L

Explanation

The amount of acid is 20% of the total volume. Multiply 0.20 by 15 liters to get 3 liters of acid.

Question 44Arithmetic Reasoning (AR)

A board 8 feet long is cut into pieces that are each 6 inches long. How many pieces are produced?

  1. 24
  2. 16 Correct answer.
  3. 12
  4. 8

Explanation

First convert feet to inches: 8 × 12 = 96 inches. Then divide by the length of each piece: 96 ÷ 6 = 16 pieces.

Question 45Arithmetic Reasoning (AR)

A dealer buys a bicycle for $400 and sells it for $460. What is the percent profit based on the cost?

  1. 6%
  2. 20%
  3. 12%
  4. 15% Correct answer.

Explanation

Profit is $460 − $400 = $60. Percent profit is profit divided by cost, so 60 ÷ 400 × 100 = 15%.

Question 46Arithmetic Reasoning (AR)

Worker A can complete a job in 12 days, and worker B can complete it in 18 days. They work together for 4 days, then A leaves. How many more days does B need to finish the job alone?

  1. 8 days Correct answer.
  2. 6 days
  3. 4 days
  4. 10 days

Explanation

The combined rate is 1/12 + 1/18 = 5/36 of the job per day. In 4 days they finish 20/36 = 5/9 of the job, leaving 4/9. At B's rate of 1/18 per day, the remaining work takes (4/9) ÷ (1/18) = 8 days.

Question 47Arithmetic Reasoning (AR)

How many liters of a 30% salt solution must be mixed with 20 liters of a 10% salt solution to obtain a 20% salt solution?

  1. 30 L
  2. 20 L Correct answer.
  3. 40 L
  4. 10 L

Explanation

Let x be the liters of 30% solution. The acid balance is 0.30x + 0.10(20) = 0.20(x + 20). Solving gives 0.10x = 2, so x = 20 liters.

Question 48Arithmetic Reasoning (AR)

A father is currently 3 times as old as his son. In 12 years, he will be twice as old as his son. How old is the son now?

  1. 8
  2. 18
  3. 12 Correct answer.
  4. 10

Explanation

Let the son's age be s, so the father is 3s. In 12 years the equation is 3s + 12 = 2(s + 12), which simplifies to 3s + 12 = 2s + 24, so s = 12.

Question 49Arithmetic Reasoning (AR)

A price is increased by 20% and then the new price is reduced by 20%. What is the overall change?

  1. rises 4%
  2. falls 4% Correct answer.
  3. no change
  4. falls 2%

Explanation

After a 20% increase the price is 1.20 times the original, and a 20% decrease multiplies that by 0.80. The net factor is 1.20 × 0.80 = 0.96, which is a 4% decrease from the original price.

Question 50Arithmetic Reasoning (AR)

How many different two-person committees can be formed from a group of 6 people?

  1. 15 Correct answer.
  2. 36
  3. 12
  4. 30

Explanation

Choose 2 people from 6, and divide by 2 because the order of the pair does not matter. The count is (6 × 5) ÷ 2 = 15.