Question

Can someone please answer this Einstein riddle!!! Rachel drives 113 miles from Pittsburg to Cleveland averaging 30 miles per hour. How fast must she drive on the return trip to average 60 miles per hour overall?

Answer 1

90 mph

Explanation:

Average speed is given by

Average speed=(initial+final speed)/2

Given average speed of 60 mph then considering initial speed of 30 mph. Let x be the final speed hence

60=(30+x)/2

120=30+x

X=120-30=90 mph

Therefore, the return trip speed is 90 mph