A man rows the same distance upstream and downstream and takes twice as long upstream as downstream. What is the ratio of the speed of the boat in still water to the speed of the stream?
A
2 : 1
B
3 : 2
C
3 : 1
D
4 : 3
Correct Option:
C
Explanation
Let the speed of the boat in still water be u and the speed of the stream be v. Upstream and downstream speeds are u - v and u + v. If upstream time is twice downstream time for the same distance, 1/(u - v) = 2/(u + v). Thus u + v = 2u - 2v, giving u = 3v. Therefore, the ratio is 3:1.
