Question

A man can row 6 km/hr. in still water. It takes him twice as long to row up as to row down the river. Find the rate of stream

• A. 2 kmph
• B. 4 kmph
• C. 6 kmph
• D. 8 kmph

Answer 1

Answer:

A. 2 kmph

Let man’s rate upstream = x km/hr.

Then, man’s rate downstream = 2x km/hr.

∴ Man’s rate in still water

$=\frac{1}{2}(x+2x)$  km/hr.

∴ $\frac{3x}{2}=6$

⇒ x = 4 km/hr.

Thus, man’s rate upstream = 4 km/hr.

Man’s rate downstream = 8 km/hr.

∴ Rate of stream

$=\frac{1}{2}(8-4)$  km/hr

$=\frac{4}{2}$

= 2 km/hr.