Rob drove to his friends house and back. IT took one hour less time to get there than it did to get back. The average speed on the trip there was 80km/h. the average speed on the way back was 60km/h. How many hours did the trip there take?

Answer 1

Let the time for the faster trip be t hrs
then the time for the slower trip was t+1

Distance for faster trip = 80t
distance for slower trip = 60(t+1)
but the distances were equal

80t = 60(t+1)
80t = 60t + 60
20t = 60
t = 3

It took 3 hours to go "there" and 4 hours to come back, each trip being 240 km.