An emergency vehicle travels 10 miles at a speed of 50 miles per hour. How fast must the vehicle travel on return trip if the round trip travel time is to be 20 minutes?
75 mph
70 mph
65 mph
80 mph
Explanation:
Going trip time = t = dsds = 1050 × 601050 × 60 = 12 minutes.
Given total time = 20 minutes
Return trip time = Total time - Going trip time = 20 - 12 = 8 minutes = 860860 hours.
As the distance is 10 miles during even return trip,
The return speed = dtdt = 1086010860 = 10 × 60810 × 608 = 75 mph.