A man takes half time in rowing a certain distance downstream than upstream. What is the ratio or the speed in still water to the speed of current?

Let the speed in still water = s kmph and the speed of current = c kmph. Let distance is D km.

Speed upstream = Speed in still water + Speed of current = s + c.

Speed downstream = Speed in still water – Speed of current = s – c.

Time upstream = Distance/Speed upstream = D/(s –c) …(1) and

Time downstream = Distance/Speed downstream = D/(s+c) …(2)

By the condition given in question Time upstream/2 = Time downstream