A car travels the 120 miles from a to b at 60 miles per hour, and then returns to a on the same road. If the average rate of the round trip is 45 miles per hour, what is the rate, in miles per hour, of the car traveling back from b to a ?
+36916 The car travels a total of 120 + 120 = 240 miles
rate x time = distance
time = distance/rate
time = 240mi / 45 mi/hr = 240/45 = 5.3333333333333333 hr
120 mi / 60 mi/hr = 2 hours for first leg of the trip
Return trip takes 5.33333 - 2 hours = 3.33333 hrs
rate times time = distance
rate = distance/time
rate = 120 / 3.3333 = 36 mi /hr
