It took peter 3 hours to drive to his friend in connecticut when he was driving with the average speed 54 mph. how much time will the way back take if peter drives with the average speed 60 mph?

The distance is the same. So the two conditions (driving there and driving back) can be equated.

There

t = 3 hours

d = d

r = 54 mph

Back

t = ?

d = d

r = 60 mph

Basic Formula

d = r * t

Solution

54 * 3 = 60 * t            Combine the left side

162 = 60 * t                Divide by 60  on both sides

162 / 60 = t                Combine

2.7  hours = time coming back.

0.7 hours = 60 * 0.7 = 42 which is in minutes.

2 hours and 42 minutes.  Answer