Saim can row 9 km/hr in still water. It takes him twice as long to row upstream as to row downstream. What is the rate of flow of the stream?
Q1. Saim can row 9 km/hr in still water. It takes him twice as long to row upstream as to row downstream. What is the rate of flow of the stream?
Answer: 3 km/h
Explanation: If downstream time is t, upstream time is 2t for the same distance; still-water speed = 9 km/h, so (9−c)/(9+c) = 1/2, giving current speed c = 3 km/h.