Ms. Peters drove from her home to the park at an average speed of 30 miles per hour and returned home along the same route at an average speed of 40 miles per hour. If her driving time from home to the park was 20 minutes, how many minutes did it take Ms. peters to drive from the park to her home?

3 answers

20 minutes (1/3 hr) at 30 mi/hr is 10 miles.

10mi/(40 mi/hr) = 1/4 hr = 15 minutes
or, you can reason that since her speed is 4/3 as great, the time required is 3/4 as much, or 15 minutes.
It was wrong!