A boat running upstream takes 8 hours 48 minutes to cover a certain distance, while it take 4 hours to cover the same distance running downstream. What is the ratio between the speed of the boat and speed of the water current respectively?

A. 1:3
B. 3:8
C. 6:3
D. 8:3
Ans: D

Explanation:

Let the man rate upstream be x kmph and that downstream be y kmph. Then,
Distance covered upstream in 8 hrs 48 min. = Distance covered downstream in 4 hrs.
=> [x 8 4/5] = (y * 4) ? 44/5 x = 4y ? y = 11/5 x.
=> Required ratio = [y + x / 2] : [6x / 5 * 1/2] : [6x / 5 * 1/2]
                            = 8/5 : 3/5 = 8:3