Castel drove to the lake and back. It took three hours less time to get there than it did to get back.

Question

Castel drove to the lake and back. It took three hours less time to get there than it did to get back. The average speed on the trip there was 70 km/h. The average speed on the way back was 28 km/h. How many hours did the trip there take?

***Note

Please explain the answer in-depth as to how you arrived to the conclusion. Thank

Answer 1

Let x = the time it took to get to the lake. Then x + 3 = time it took to get back.

distance = rate x time

Distance there = rate there * time there = 70x

Distance back = rate back * time back = 28(x + 3)

distance there = distance back

70x = 28(x + 3)

70x = 28x + 84

42x = 84

x = 2