Discussion Forum

A man swimming in a stream which flows 1.5 kmph, finds that in a given time he can swim twice as fast with the stream as he can against it. At what rate does he swim ?

Answer:

Explanation:

Rate of stream $=1.5$ km/hr

Let speed of man in still water $=x$ km/hr and Distance $=d$

Upstream speed $=(x-1.5)$ km/hr Downstream speed $=(x+1.5)$ km/hr

Given, $\frac{2d}{(x+1.5)}$ $=\frac{d}{(x-1.5)}$

$\Rightarrow 2x-3$ $=x+1.5$ $\Rightarrow x$ = 4.5 km/hr.