A man can row at 5 kmph in still water. If the velocity of current is 1 kmph and it takes him 1 hour to row to a place and come back, how far is the place?

Speed downstream = (5 + 1) kmph = 6 kmph.
Speed upstream = (5 - 1) kmph = 4 kmph.

Let the required distance be x km.
Then, x/6 + x/4 = 1
2x + 3x = 12
5x = 12
x = 2.4 km.