Banking Quantitative Aptitude Sample Paper Quantitative Aptitude Sample Paper-3

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

A) 1 km/h

B) 1.5 km/h

C) 1.8 km/h

D) 3.6 km/h

Correct Answer: A

Solution :

[a] Suppose he moves 4 km downstream in x h. Then,

Speed downstream \[=\left( \frac{4}{x} \right)\,\,km/h\]

Speed upstream \[=\left( \frac{3}{x} \right)\,\,km/h\]

\[\therefore \] \[\frac{48}{(4/x)}+\frac{48}{(3/x)}-14\]\[\Rightarrow \]\[x=\frac{1}{2}\]

So, speed downstream \[=8\text{ }km/h,\]

Speed upstream \[=6\text{ }km/h\]

Rate of the stream \[=\frac{1}{2}(8-6)km/h=1km/h\]