GED — All Questions

What is 0.6 written as a percent?

• a.0.6%
• b.600%
• c.6%
• d.60%✓

To convert a decimal to a percent, multiply by 100, so 0.6 becomes 60%. This moves the decimal point two places to the right. Percent means 'out of one hundred.'

A box contains 3 red, 4 blue, and 5 green marbles. What is the probability of drawing a blue marble at random?

• a.1/2
• b.1/4
• c.5/12
• d.1/3✓

Probability is favorable outcomes over total outcomes. There are 4 blue marbles out of 3 + 4 + 5 = 12, so the probability is 4/12, which reduces to 1/3. The 1/4 figure is the probability of drawing a red marble (3 out of 12), and 5/12 is the probability of drawing a green one — both are answers to a question that was not asked. And 1/2 would require six blue marbles rather than four.

If 5 pencils cost $1.25, how much do 8 pencils cost at the same rate?

• a.$1.85
• b.$1.60
• c.$2.00✓
• d.$2.50

Each pencil costs $1.25 ÷ 5 = $0.25, so 8 pencils cost 8 × $0.25 = $2.00. Finding the unit rate lets you scale to any quantity. Unit pricing is a common real-world calculation.

What is the value of the expression -4 + 9 − 3?

• a.2✓
• b.10
• c.8
• d.-10

Working left to right: -4 + 9 = 5, and 5 − 3 = 2. Adding a positive to a negative moves toward zero and beyond. Careful sign handling gives the correct result of 2.

A square has a perimeter of 36 cm. What is the length of one side?

• a.12 cm
• b.9 cm✓
• c.18 cm
• d.6 cm

A square has four equal sides, so divide the perimeter by 4: 36 ÷ 4 = 9 cm. Perimeter is the total distance around a shape. Each side of this square measures 9 cm.

Which value of x makes the equation 2x = 5x − 12 true?

• a.6
• b.4✓
• c.3
• d.2

Subtract 2x from both sides to get 0 = 3x − 12, then add 12 and divide by 3 to find x = 4. Gathering variables on one side isolates x. Checking: 2(4) = 8 and 5(4) − 12 = 8, which matches.

The temperature rose from -5°F to 12°F. By how many degrees did it rise?

• a.17°F✓
• b.12°F
• c.7°F
• d.-17°F

The change equals 12 − (−5) = 12 + 5 = 17 degrees. Subtracting a negative is the same as adding its positive. The temperature climbed 17°F.

What is 3/5 + 1/5?

• a.4/5✓
• b.2/5
• c.3/25
• d.4/10

When fractions share a denominator, add the numerators: 3 + 1 = 4, giving 4/5. The denominator stays the same at 5. This result is already in lowest terms.

A phone plan costs $30 per month plus $0.10 per text. Which expression gives the total monthly cost for t texts?

• a.30 + 0.10t✓
• b.30t + 0.10
• c.30.10t
• d.30 + 0.10 + t

The $30 fee is charged once whatever happens, so it stands alone; the 10 cents is charged per text, so it is multiplied by the number of texts. That gives 30 + 0.10t. Writing 30t + 0.10 swaps the two roles, charging $30 per text and a flat dime a month. Writing 30 + 0.10 + t adds the number of texts to the money instead of multiplying, which mixes a count with dollars. And 30.10t charges the whole $30.10 for every single text.

What is the median of the data set 7, 3, 9, 5, 11?

• a.35
• b.5
• c.9
• d.7✓

First order the numbers: 3, 5, 7, 9, 11; the middle value is 7. The median is the center of an ordered list. With five values, the third number is the median.

If a triangle has angles measuring 40° and 75°, what is the third angle?

• a.75°
• b.55°
• c.65°✓
• d.115°

The angles of a triangle sum to 180°, so 180 − 40 − 75 = 65°. This triangle-angle-sum rule holds for every triangle. The missing angle measures 65 degrees.

Expand the expression 4(2x + 3).

• a.6x + 7
• b.8x + 12✓
• c.8x + 7
• d.8x + 3

Use the distributive property to multiply 4 by each term: 4 × 2x = 8x and 4 × 3 = 12. The result is 8x + 12. Distribution multiplies the outside factor across everything inside the parentheses.

A worker earns $18 per hour and works 35 hours in a week. What are the weekly earnings?

• a.$720
• b.$53
• c.$530
• d.$630✓

Multiply the hourly rate by hours worked: 18 × 35 = 630 dollars. Total pay equals rate times time. The worker earns $630 that week.

What is the square root of 144?

• a.11
• b.72
• c.12✓
• d.14

The square root of 144 is the number that, multiplied by itself, gives 144; that number is 12 because 12 × 12 = 144. Square roots reverse the squaring operation. Note that 72 is half of 144, not its root.

A number increased by 20% becomes 60. What was the original number?

• a.48
• b.50✓
• c.40
• d.72

If the original number is x, then 1.20x = 60, so x = 60 ÷ 1.20 = 50. Increasing by 20% multiplies by 1.20. Reversing the increase means dividing by 1.20.

Two angles are complementary. If one measures 35°, what is the other?

• a.45°
• b.145°
• c.55°✓
• d.65°

Complementary angles add up to 90°, so the other angle is 90 − 35 = 55°. Complementary differs from supplementary, which sums to 180°. The missing angle is 55 degrees.

Which part of a plant cell captures light energy for photosynthesis?

• a.Cell wall
• b.Ribosome
• c.Nucleus
• d.Chloroplast✓

Chloroplasts contain chlorophyll, the pigment that absorbs sunlight to power photosynthesis. The nucleus stores genetic material, and ribosomes build proteins. Photosynthesis converts light energy into chemical energy stored in sugars.

What is the chemical formula for water?

• a.H2O✓
• b.O2
• c.CO2
• d.NaCl

Water is made of two hydrogen atoms and one oxygen atom, giving the formula H2O. CO2 is carbon dioxide and NaCl is table salt. Chemical formulas show the types and numbers of atoms in a molecule.

In a food chain, organisms that make their own food using sunlight are called—

• a.decomposers
• b.producers✓
• c.predators
• d.consumers

Producers, such as green plants, make their own food through photosynthesis and form the base of a food chain. Consumers eat other organisms, and decomposers break down dead matter. Energy flows from producers to consumers.

Which gas do humans need to breathe in to survive?

• a.Nitrogen
• b.Carbon dioxide
• c.Hydrogen
• d.Oxygen✓

Humans inhale oxygen, which cells use to release energy from food through respiration. We exhale carbon dioxide as a waste product. Although nitrogen is the most abundant gas in air, the body does not use it for respiration.

A scientist records that a substance boils at 100°C at sea level. Boiling point is an example of a—

• a.chemical formula
• b.chemical change
• c.living factor
• d.physical property✓

Boiling point is a physical property because it can be measured without changing the substance's identity. A chemical change would produce a new substance. Physical properties include color, density, and melting point.

Which of the following best describes the function of the heart?

• a.It produces digestive enzymes.
• b.It filters waste from the blood.
• c.It pumps blood around the body.✓
• d.It controls breathing rate.

The heart is a muscular pump, and circulating blood is the whole of its job: it moves oxygen and nutrients out to the tissues and carries waste away. Filtering waste from the blood is the kidneys' work. Producing digestive enzymes is done by the pancreas and the glands of the gut. And breathing rate is set by the brainstem, not by the heart, although the two adjust together during exercise.

What force pulls objects toward the center of the Earth?

• a.Gravity✓
• b.Friction
• c.Electricity
• d.Magnetism

Gravity is the force that attracts objects toward Earth's center, giving them weight. Friction resists motion between surfaces, and magnetism acts on certain metals. Gravity keeps us and objects on the ground.

A trait passed from parents to offspring through genes is called—

• a.an instinct
• b.a learned behavior
• c.an inherited trait✓
• d.an adaptation

Inherited traits, such as eye color, are passed genetically from parents to offspring. Learned behaviors are acquired through experience, not genes. Genes carry the instructions that determine inherited characteristics.

During the water cycle, what process turns liquid water into water vapor?

• a.Precipitation
• b.Condensation
• c.Evaporation✓
• d.Collection

Evaporation is the change of liquid water into vapor, usually driven by heat from the sun. Condensation is the reverse, forming clouds, and precipitation returns water as rain or snow. Evaporation moves water into the atmosphere.

Which of these is a renewable energy source?

• a.Natural gas
• b.Solar power✓
• c.Petroleum
• d.Coal

Solar power comes from sunlight, which is replenished continuously, making it renewable. Coal, natural gas, and petroleum are fossil fuels that take millions of years to form and can be used up. Renewable sources do not run out on a human timescale.

The smallest unit of life capable of carrying out all life processes is the—

• a.atom
• b.cell✓
• c.molecule
• d.organ

The cell is the basic structural and functional unit of all living things. Atoms and molecules are smaller but are not themselves alive. Organs are made of many cells working together.

A study finds that a group of plants given fertilizer grew taller than plants without it. In this experiment, fertilizer is the—

• a.conclusion
• b.control group
• c.independent variable✓
• d.dependent variable

The independent variable is the factor the scientist deliberately changes; here it is the fertilizer. The plant height that responds is the dependent variable. Well-designed experiments change only one variable at a time.

Which planet is closest to the Sun?

• a.Jupiter
• b.Venus
• c.Earth
• d.Mercury✓

Mercury is the innermost planet, orbiting nearer the Sun than any other. Venus is the second planet out and Earth the third, which is why both are common wrong picks. Jupiter is the fifth planet and far beyond all of them. Distance from the Sun drives a planet's temperature and the length of its year.

When wood burns, it turns to ash and gas. This is an example of a—

• a.chemical change✓
• b.reversible change
• c.physical change
• d.change of state

Burning is a chemical change because new substances, such as ash and gases, form and cannot easily be turned back into wood. Physical changes, like melting, do not create new substances. Chemical changes rearrange atoms into different compounds.

What do we call the variety of living organisms in an ecosystem?

• a.Community
• b.Climate
• c.Population
• d.Biodiversity✓

Biodiversity is the range of different species living in an area. A community is all the populations living together in that area — a related idea, but it names the assemblage rather than its variety. A population is a single species, so it cannot describe variety at all. And climate describes long-term weather patterns, not living things. High biodiversity tends to make an ecosystem more stable.

The process by which a species changes over many generations in response to its environment is called—

• a.condensation
• b.circulation
• c.digestion
• d.evolution✓

Evolution is the gradual change in inherited traits of a population over generations, often through natural selection. It explains how species adapt to their environments over long periods. Individuals do not evolve; populations do.

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

• a.Capillaries
• b.Nerves
• c.Veins
• d.Arteries✓

An artery is defined by direction: it carries blood away from the heart. Note that this is about direction and not oxygen — the pulmonary arteries carry oxygen-poor blood from the heart to the lungs, which is the exception that shows what the definition really rests on. Veins run the other way, returning blood to the heart. Capillaries are the fine vessels between the two where gases and nutrients are exchanged with the tissues. Nerves carry electrical signals and are not blood vessels at all.

A graph shows a town's average temperature rising steadily each decade. This trend best supports the idea of—

• a.climate change✓
• b.seasonal change
• c.daily weather
• d.an eclipse

A steady rise held across decades is a climate signal, because climate is precisely the long-run pattern rather than any single reading. Daily weather is the wrong timescale — it swings far more than this in a single afternoon. Seasonal change is also the wrong timescale, and it repeats each year instead of trending in one direction. And an eclipse is a brief astronomical event with no bearing on a decades-long temperature record.

Which of the following is a chemical property of a substance?

• a.Its density
• b.Its ability to rust✓
• c.Its hardness
• d.Its boiling point

Rusting is iron reacting with oxygen to form a new substance, so the ability to rust describes how the material behaves chemically. Density, hardness and boiling point can all be measured without turning the substance into anything else, which is exactly what makes them physical properties. The dividing line is whether observing the property destroys the original substance: weigh it, scratch it or boil it and you still have the same material, but rust it and you do not.

In the human body, which system is responsible for breaking down food into nutrients?

• a.Respiratory system
• b.Nervous system
• c.Digestive system✓
• d.Skeletal system

The digestive system breaks food down into nutrients the body can absorb and use. The respiratory system handles gas exchange, and the nervous system sends signals. Digestion begins in the mouth and continues through the stomach and intestines.

Which of these best explains why ice floats on water?

• a.Ice is less dense than water.✓
• b.Ice contains more salt than water.
• c.Ice has more mass than water.
• d.Ice is warmer than water.

Water is unusual: as it freezes its molecules lock into an open lattice that takes up more room than the liquid, so a given mass of ice occupies more volume and is therefore less dense. Anything less dense than the fluid around it floats. Ice does not contain more salt than the water it forms from — freezing tends to exclude salt. Having more mass is irrelevant without knowing volume, since density is mass per unit volume. And ice is colder than liquid water, not warmer.

Bacteria that break down dead plants and animals are known as—

• a.producers
• b.herbivores
• c.decomposers✓
• d.predators

Decomposers, including many bacteria and fungi, break down dead organisms and return nutrients to the soil. This recycling supports new plant growth. Without decomposers, dead matter and nutrients would accumulate unused.

A meteorologist predicts rain based on falling air pressure. Air pressure is measured with a—

• a.thermometer
• b.barometer✓
• c.telescope
• d.anemometer

A barometer measures air pressure, which helps forecast weather changes. A thermometer measures temperature and an anemometer measures wind speed. Falling air pressure often signals approaching storms.

Which statement correctly describes an atom?

• a.It is the smallest unit of a compound.
• b.It is a particle found only in metals.
• c.It is the smallest living thing.
• d.It is the smallest unit of an element.✓

An atom is the smallest particle of an element that still has that element's properties. The smallest unit of a compound is a molecule, not an atom, which is the near-miss worth learning. Atoms are not confined to metals — every element, including the gases you are breathing, is made of them. And the smallest living thing is a cell, which is built from enormous numbers of atoms and is a different order of thing entirely.

The energy stored in food is a form of—

• a.chemical energy✓
• b.light energy
• c.sound energy
• d.kinetic energy

Food stores chemical energy in the bonds of its molecules, which the body releases during digestion and respiration. Kinetic energy is energy of motion. Cells convert this chemical energy into usable forms to power life processes.

Which action would most reduce the amount of waste sent to landfills?

• a.Sending yard waste to the landfill
• b.Recycling paper, glass, and plastic✓
• c.Buying products with extra packaging
• d.Using more disposable items

Recycling diverts paper, glass and plastic out of the waste stream and back into manufacturing, so the material never reaches the landfill at all. Sending yard waste there does the opposite: it is organic matter that could be composted, and it adds directly to landfill volume. Buying products with extra packaging increases waste before the item is even used. And using more disposable items replaces things that would have been reused, which raises the volume thrown away.

A scientist repeats an experiment several times and gets similar results. This repetition mainly helps to—

• a.change the independent variable
• b.make the results more reliable✓
• c.prove the hypothesis is a law
• d.eliminate the need for a control

Repeating an experiment and getting consistent results makes the findings more reliable and trustworthy. Repetition helps rule out chance errors. Reliable, reproducible data is a cornerstone of the scientific method.

Which document begins with the words 'We the People' and establishes the framework of the U.S. government?

• a.The U.S. Constitution✓
• b.The Bill of Rights
• c.The Emancipation Proclamation
• d.The Declaration of Independence

The U.S. Constitution opens with 'We the People' and sets up the structure of the federal government. The Declaration of Independence announced separation from Britain. The Bill of Rights is the first ten amendments to the Constitution.

The U.S. government is divided into three branches. Which branch makes the laws?

• a.Legislative✓
• b.Executive
• c.Judicial
• d.Military

The legislative branch, Congress, makes the laws. The executive branch enforces them and the judicial branch interprets them. This separation of powers prevents any one branch from becoming too strong.

What is the main purpose of the Bill of Rights?

• a.To list the duties of the president
• b.To declare war on Britain
• c.To protect individual freedoms✓
• d.To set tax rates

The Bill of Rights, the first ten amendments, protects individual liberties such as free speech and religion. It limits the power of the federal government over citizens. These protections were added to gain support for ratifying the Constitution.

In an economy, what does the term 'supply' refer to?

• a.The tax on a product
• b.The total money in a bank
• c.The desire of consumers to buy a good
• d.The quantity producers offer for sale✓

Supply is the quantity of a good producers are willing to offer at a given price. The desire of consumers to buy is demand, the other half of the pair, and confusing the two reverses every prediction you would make about price. The total money in a bank is a measure of deposits and has nothing to do with the market for a particular good. And a tax on a product shifts supply but is not itself supply.

Which right is protected by the First Amendment?

• a.The right to a speedy trial
• b.Protection from unreasonable searches
• c.Freedom of speech✓
• d.The right to bear arms

The First Amendment protects freedoms of speech, religion, press, assembly, and petition. The right to bear arms is in the Second Amendment. Knowing which amendment covers which right is a core civics concept.

The American Civil War (1861-1865) was fought largely over which issue?

• a.Trade with China
• b.Women's right to vote
• c.Independence from Britain
• d.Slavery and its expansion✓

The war followed decades of conflict over slavery and, above all, over whether it would spread into the western territories; the seceding states said so in their own declarations of causes. Independence from Britain was the Revolutionary War, roughly eighty years earlier. Women's suffrage was a separate nineteenth- and twentieth-century movement that culminated in 1920. And trade with China had no bearing on secession.

What is inflation?

• a.A drop in the population
• b.A type of government tax
• c.An increase in exports only
• d.A general rise in prices✓

Inflation is a sustained rise in the overall price level, which means each dollar buys less than it did. The word 'general' is doing the work: one product getting dearer is not inflation. A tax is a government charge, not a movement in prices, though taxes can feed into them. A drop in population is a demographic change with no direct definition in terms of prices. And a rise in exports alone describes trade, not the price level.