Question
A river d km wide is flowing at rate 
A swimmer who can swim with velocity 
relative to water, dives into the river perpendicular to the direction of flow to cross the river. How far he will go down the river along the river.
Solution
Given,
Width f the river = d
Rate of flow of river = v1 m/s
Rate of flow of the swimmer = v2 m/s
Distance moved by the swimmer along the river is given by,
