SAT Word Problems Practice Flashcards

A population of bacteria doubles every 3 hours. Starting with 500 bacteria, how many will there be after 12 hours?

Answer: 8,000

12 hours = 4 doubling periods. Count = 500 × 2⁴ = 500 × 16 = 8,000.

A cyclist rides 15 mph for part of a 60-mile trip and 10 mph for the rest. The trip takes 5 hours. How many miles did the cyclist ride at 15 mph?

Answer: 30

d/15 + (60−d)/10 = 5 → multiply by 30: 2d + 3(60−d) = 150 → −d = −30 → d = 30.

Three consecutive odd integers have a sum of 51. What is the product of the largest and smallest?

Answer: 285

n + (n+2) + (n+4) = 51 → n = 15. Smallest = 15, largest = 19. Product = 15 × 19 = 285.

A school has 850 students. Each takes math, science, both, or neither. 600 take math, 500 take science, and 100 take neither. How many take both?

Answer: 350

Students in at least one = 750. By inclusion-exclusion: 600 + 500 − both = 750 → both = 350.

A shirt costs $45. It is discounted 20%, then an additional 10% off the sale price. What is the final price?

Answer: $32.40

After 20% off: $36. After 10% off that: $36 × 0.90 = $32.40.

A $1,000 investment earns 8% interest compounded annually. What is it worth after 3 years? (Approximate to the nearest dollar.)

Answer: $1,240

A = 1000 × (1.08)³ = 1000 × 1.2597 ≈ $1,260. Set answers: ['$1,240','$1,260','$1,295','$1,331'], correct=1.

A bag contains 3 times as many dimes as quarters. The total value is $2.75. How many quarters are in the bag?

Answer: 5

Let q = quarters, d = 3q dimes. 0.25q + 0.10(3q) = 2.75 → 0.55q = 2.75 → q = 5.