A man can row 4 km/h in still water. If the river is flowing at 2 km/h, how long will it take him to row 10 km upstream and back?
Q1. A man can row 4 km/h in still water. If the river is flowing at 2 km/h, how long will it take him to row 10 km upstream and back?
Answer: 5 hours
Explanation: Upstream speed = 4 - 2 = 2 km/h. Time taken to row 10 km upstream = 10 / 2 = 5 hours. Downstream speed = 4 + 2 = 6 km/h. Time taken to row 10 km downstream = 10 / 6 = 1.67 hours.