Anand can row 8 km/h in still water. It takes him thrice as long to row up as to row down the stream. Find the speed of the stream.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 4 km/h.
Speed of boat = 8 km/h
Let's assume the speed of the stream is x and the distance is D.
It takes three times as much time to run a boat in the downstream direction as compared to running a boat in the opposite direction.
According to the question,
3D/(8 + x) = D/(8 - x)
(8 - x)/(8 + x) = 1/3
x = 16/4
x = 4 km/h