Discussion Forum

A man rows to a place 48 km distant and back in 14 hours. He finds that he can row 4 km with the stream in the same time as 3 km against the stream. The rate of the stream is :

Answer:

Explanation:

Suppose he moves 4 km downstream in $x$ hours. Then,

Speed downstream $=\frac{4}{x}$ km/hr, Speed upstream $=\frac{3}{x}$ km/hr

$\left(\frac{48}{\frac{4}{x}}\right)+\left(\frac{48}{\frac{3}{x}}\right)$ $=14$ or $x=\frac{1}{2}$

So, Speed downstream = 8 km/hr, Speed upstream = 6 km/hr.

Rate of the stream $=\frac{1}{2}(8-6)$ km/hr = 1 km/hr.