A man swims downstream 72 km and upstream 45 km taking 9 hours each time; what is the speed of the current?
Q1. A man swims downstream 72 km and upstream 45 km taking 9 hours each time; what is the speed of the current?
Answer: 1.5 kmph
Explanation: Downstream speed = 72/9 = 8 kmph; upstream speed = 45/9 = 5 kmph; current speed = (8 − 5)/2 = 1.5 kmph.