Question

The time it took for a man to walk from his house to the park and back was 2 hours. The distance from his house to the park is 7 miles. The rate at which he walked to the park was twice the rate at which he walked back. What is the man's rate (in mph) walking back to his house?

Answer 1

5.25 mph

Explanation:

Let r represent the rate at which the man walked back from the park. Then 2r is the rate at which he walked to the park. His total travel time is ...

time = distance/speed

total time = time to the park + time from the park

2 = 7/(2r) +7/r

2 = (7 +14)/(2r) . . . combine terms

r = 21/(2·2) = 5.25 . . . miles per hour

The man's rate walking back from the park is 5.25 miles per hour.