Bluebook SAT Test SAT Word Problems Practice 4

Question 1

A pool is filled by two hoses. Hose A fills it in 8 hours and Hose B in 12 hours. How long does it take with both hoses running together?

Accepted Answer

4.8 hours

Answer

Combined rate = 1/8 + 1/12 = 5/24. Time = 24/5 = 4.8 hours.

Question 2

A jacket's price was reduced by 30%, and then the reduced price was increased by 20%. What is the overall percent change?

Accepted Answer

−16%

Answer

Start at $100. After 30% decrease: $70. After 20% increase: $84. Net change = −16%.

Question 3

The length of a rectangle is increased by 25% and the width is decreased by 20%. By what percent does the area change?

Accepted Answer

0%

Answer

New area = (1.25l)(0.80w) = 1.00lw. The area is unchanged, so the change is 0%.

Question 4

A boat travels 48 miles downstream in 3 hours and the same distance upstream in 4 hours. What is the speed of the current in mph?

Accepted Answer

2

Answer

Downstream speed = 16 mph; upstream speed = 12 mph. Current = (16 − 12)/2 = 2 mph.

Question 5

In 5 years, Maria will be twice as old as she was 4 years ago. How old is Maria now?

Accepted Answer

13

Answer

x + 5 = 2(x − 4) → x + 5 = 2x − 8 → x = 13.

Bluebook SAT Practice Test