If a girl takes twice as long as to row a distance against the stream as to row the same distance in the direction of the stream, then the ratio of speed of the girl in still water to the speed of stream is :
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 3 : 1
Let her speed in still water be u and the speed of the stream v. For the same distance, twice the time means half the speed, so the downstream speed is twice the upstream speed:
\( \displaystyle u+v=2(u-v) \)
\( \displaystyle u=3v \)
So u : v = 3 : 1.