Question

John went on a bike ride to the store 4 miles away. If it took John 3/10 of an hour to get there and 1/2 of an hour to get back, what was his average rate of speed (miles per hour) for the entire trip?

Answer 1

The round trip was 8 miles ( 4 + 4 = 8)

The total time for the trip is 3/10 + 1/2

Rewrite 1/2 as 5/10

Now add 3/10 + 5/10 = 8/10 = 4/5 hour for the 8 mile trip.

Now to find miles per hour, divide total miles by total time:

8 miles / 4/5 hour

When you divide by a fraction flip the fraction over and multiply:

8 x 5/4 = 40/4 = 10

The average rate was 10 miles per hour.