Question

A man can row three-quarters of a kilometre again the stream in 45/4 minutes and return it 15/2 minutes. The speed of the man in still water is

• A. 2 km/hr
• B. 3 km/hr
• C. 4 km/hr
• D. 5 km/hr

Answer 1

The correct option is D 5 km/hr

Speed upstream
$=(\frac{3}{4}\times \frac{4}{45}\times 60)$
= 4 kmph

Speed downstream
$=(\frac{3}{4}\times \frac{2}{15}\times 60)kmph$
= 6 kmph.

Speed in still water
$=\frac{1}{2}(6+4)kmph$
= 5 kmph