A man can row a boat at a speed of 20 km/hr in still water. If the speed of the stream is 5 km/hr, in what time in hours he can row a distance of 75 km downstream?

3

Given:

• Speed in still water = 20 km/hr
• Speed of stream = 5 km/hr
• Distance downstream = 75 km

Downstream speed:

$20 + 5 = 25\text{ km/hr}$

Time taken:

$\text{Time} = \frac{\text{Distance}}{\text{Speed}} = \frac{75}{25} = 3\text{ hours}$