Jason drives uphill from home to school, averaging 20 miles per hour. On the way back, he drives back downhill from school to home at 60 miles an hour. What was the average speed in miles per hour for his round trip?

Average velocity = 30 miles per hour

Explanation:

Given that

Velocity for uphill = 20 miles per hour

Velocity for downhill = 60 miles per hour

We know that

Distance = Velocity x time

Total distance = Average velocity x total time

Lets take distance from home to school is s

Time taken from home to school = s/20 hr

Time taken from school to home = s/60 hr

Total time = s/20+s/60

Total distance = Average velocity x total time

s + s = Average velocity x (s/20+s/60)

So average velocity = 30 miles per hour