# Easy Time, Speed & Distance Solved QuestionAptitude Discussion

 Q. A boatman rows to a place 45 km distant and back in 20 hour. He finds that he can row 12 km with the stream in the same time as 4 km against the stream. Find the speed of the stream.
 ✔ A. 3 km/hr ✖ B. 2.5 km/hr ✖ C. 4 km/hr ✖ D. 3.5 km/hr

Solution:
Option(A) is correct

Ratio of time taken for up and down = $3:1$

Out of 20 hr he took 15 hr for up and 5 for down.

Speed up = $\dfrac{45}{15}=3$

and down = $\dfrac{45}{5}=9$

Hence speed of stream

$(9âˆ’3)\times \dfrac{1}{2}$

3 km/hr

## (1) Comment(s)

NerdBird
()

Was it supposed to be (9-3) x 1/2?