Question

The distance between two cities is ninety miles, and a woman drives from one city to the other at a rate of 45 mph. At what rate must she return if the total travel time is three hours and forty minutes?



27 mph
45 mph
54 mph

Answer 1

54

Answer 2

distance = 90 mi ; v = 45 mph ; time = d/v = 2 hrs.
distance = 90 mi ; time = [3 2/3 - 2] = 1 2/3 hrs
v = 90/(5/3) = 54 mph

Answer 3

you can use this formula:
rate = distance/time