1.  A man can row at 5 kmph in still water is 15 km/hr and the rate of current is 1 kmph and it takes him 1 hour to row to a place and come back, how far is the place ?
A. 2.4 km
B. 2.5 km
C. 3 km
D. 3.6 km

Answer: Option A

Explanation:

Speed downstream = (5 + 1) kmph = 6 kmph.

Speed upstream = (5 - 1) kmph = 4 kmph.

Let the required distance be x km.

Then, x + x = 1
6 4

2x + 3x = 12

5x = 12

x = 2.4 km.