Answer:
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