Asked by Coco

A cyclist bikes x distance at 10 miles per hour and returns over the same path at 8 miles per hour. What is the cyclist’s average rate for the round trip in miles per hour?
Answered by Ms. Sue
It seems to me that you need the average of 10 and 8.
18/2 = 9 mph
Answered by Reiny
No, it's not that simple
Time for first trip = x/10
time for second trip =x/8
distance of total trip = 2x

rate = total distance/total time
=2x/(x/10 +x/8)
=..
=..
=8.88 mph