Question

When Lyn walks from home to school at a speed of 3 mph, it takes her 25 minutes. How long will it take her if she runs at a speed of 5 mph?

Answer 1

The distance from home to school is (3 mph)(25/60) hr, or 1.25 miles.

Now divide this 1.25 miles by 5 mph to get the time required at 5 mph:


1.25 mi
----------- = 0.25 hr, or 15 minutes.
5 mi/hr

Answer 2

25 / (5/3) is 15, so 15 minutes