Free SAT Practice Questions

Sample Practice Questions

Try these 10 sample questions from the SAT practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1Oyster reefs shelter fish and crabs in crevices, and oysters filter algae from surrounding water as they feed. In some places, reefs also lessen the force of waves reaching the shore. Which choice best states the main idea of the text?

   1. A.Oyster reefs provide several ecological benefits in coastal waters.Correct answer: A
   2. B.Oysters depend on shore vegetation for all of their food.
   3. C.Most coastal fish spend their entire lives inside oyster reefs.
   4. D.The principal purpose of oyster reefs is to increase wave energy.

   Explanation: NOAA explains that "Oysters are a crucial component of global ocean health. These animals filter and clean the surrounding water and provide habitat, food, and jobs." The passage adds wave protection to this evidence of multiple benefits. B and C make unsupported claims; D reverses the stated effect on waves.

   Reference: Oyster Reef Habitat — The Value of Oyster Reef Habitat

2. 2What value of x satisfies 3(2x − 5) = 4x + 7?

   1. A.four
   2. B.seven
   3. C.elevenCorrect answer: C
   4. D.negative eleven

   Explanation: OpenStax recommends "adding or subtracting the same quantity to or from both sides" when solving equations. Distribute to get 6x − 15 = 4x + 7; subtract 4x and add 15 to obtain 2x = 22, so x = 11. The other values do not satisfy the original equation.

   Reference: Functions and Function Notation — Evaluating Functions Expressed in Formulas

3. 3Dredging can remove oysters while also scraping away the raised structure of a reef. A damaged reef may take decades to recover, during which it provides less shelter for juvenile fish and crabs. Which inference is most directly supported by the text?

   1. A.A harvested reef always recovers within a single season.
   2. B.Repeated dredging can diminish habitat even beyond the oysters it removes.Correct answer: B
   3. C.Young fish gain shelter when dredging flattens a reef.
   4. D.Dredging leaves other species' habitat unchanged despite reef damage.

   Explanation: NOAA states, "It may take decades for a reef harvested with these methods to recover, diminishing habitat for young fish and crabs." B follows because damage affects other species. A understates recovery time, C reverses the effect on shelter, and D overlooks the effect on habitat.

   Reference: Oyster Reef Habitat — Challenges for Oyster Reefs, Unsustainable Harvesting

4. 4For what value of k is the equation 5(x + 2) = 5x + k true for every real value of x?

   1. A.negative ten
   2. B.zero
   3. C.five
   4. D.tenCorrect answer: D

   Explanation: OpenStax states, "An identity equation is true for all values of the variable." Expanding the left side gives 5x + 10, which equals 5x + k for every x only when k = 10.

   Reference: Linear Equations in One Variable — Solving Linear Equations in One Variable

5. 5Light requires time to travel through space. The light from some distant galaxies seen by the Webb telescope traveled for more than 13 billion years before reaching the telescope. What does this information most directly imply about the images of those galaxies?

   1. A.They show the galaxies as they were long before the light arrived.Correct answer: A
   2. B.They show the galaxies as they will appear 13 billion years from now.
   3. C.They show the galaxies at the same instant the light is detected.
   4. D.They show the galaxies as they appeared halfway through the light's journey.

   Explanation: NASA explains, "The light from the most distant galaxies that Webb has viewed left those galaxies over 13 billion years ago." The detected light carries information about the galaxies when it was emitted, not when it was detected, during its journey, or in the future.

   Reference: How Can Webb Study the Early Universe? — When astronomers use a telescope to look farther away, they are also looking back in time

6. 6A line passes through (−2, 5) and (4, −7). What is its slope?

   1. A.negative twoCorrect answer: A
   2. B.two
   3. C.negative one-half
   4. D.one-half

   Explanation: OpenStax describes slope as "the ratio of the vertical change in y over the horizontal change in x". Here the changes are −7 − 5 = −12 and 4 − (−2) = 6, so the slope is −12/6 = −2. The other answers reverse the sign or the ratio.

   Reference: Linear Equations in One Variable — The Slope of a Line

7. 7A research team expected to identify a few dozen galaxies from the era of reionization in a field observed with Webb. Instead, the team reported identifying 117. Which finding from the text best supports the claim that the telescope exceeded the team's expectations?

   1. A.The team expected several dozen galaxies but identified 117.Correct answer: A
   2. B.The team expected to find a few dozen galaxies.
   3. C.The team identified 117 galaxies in the field.
   4. D.The team searched for galaxies from the era of reionization.

   Explanation: The team reported, "We expected to identify a few dozen galaxies that existed during the Era of Reionization – but were easily able to pick out 117," directly comparing expectations with results. B and C give only one side of that comparison; D describes the search but does not compare the counts.

   Reference: NASA's Webb Proves Galaxies Transformed the Early Universe — Research team's discussion of first observed field

8. 8A line passes through (4, 1) and is perpendicular to the line y = (3/4)x + 2. Which equation represents the first line?

   1. A.y minus one equals three-fourths times (x minus four)
   2. B.y minus one equals four-thirds times (x minus four)
   3. C.y minus one equals negative four-thirds times (x minus four)Correct answer: C
   4. D.y minus one equals negative three-fourths times (x minus four)

   Explanation: OpenStax explains, "The slopes are negative reciprocals of each other" for perpendicular lines. The negative reciprocal of 3/4 is −4/3. Substituting the point (4, 1) yields y − 1 = −(4/3)(x − 4).

   Reference: Use the Slope-Intercept Form of an Equation of a Line — Use Slopes to Identify Perpendicular Lines

9. 9As the universe expands, light traveling from very distant galaxies is stretched to longer wavelengths. Light emitted as visible light can consequently reach Earth as infrared light. Which conclusion is best supported by these statements?

   1. A.An instrument sensitive to infrared light can detect some light emitted as visible light by distant galaxies.Correct answer: A
   2. B.An instrument sensitive only to visible light must detect all light emitted by distant galaxies.
   3. C.Expansion shortens the wavelengths of light traveling from distant galaxies.
   4. D.Galaxies emit infrared light only after their light has reached Earth.

   Explanation: NASA states, "By the time visible light from extremely distant galaxies reaches us, it appears as infrared light." Infrared sensitivity can therefore detect some such shifted light; B overlooks the shift, C reverses it, and D confuses emission with later detection.

   Reference: How Can Webb Study the Early Universe? — When astronomers use a telescope to look farther away, they are also looking back in time

10. 10For a tank being drained at a constant rate, V(t) = 145 − 6t gives the volume V in liters after t minutes. What does the number 6 represent in this model?

    1. A.The tank's initial volume, in liters
    2. B.The number of liters removed per minuteCorrect answer: B
    3. C.The number of minutes needed to remove one liter
    4. D.The tank's volume after one minute, in liters

    Explanation: OpenStax describes slope as "the ratio of the vertical change in y over the horizontal change in x". The coefficient −6 means the volume decreases by 6 liters each minute; 145 is the initial volume.

    Reference: Linear Equations in One Variable — The Slope of a Line