Question

A man can row 9 km/h in still water. It takes him twice as long as to row down. Find the rate of stream of the river ?
A)

Answer 1

Let's consider, in still water the man's real speed, x= 9km/h

Steam of the river is y

he takes twice as long as his current speed to row down which is 9/2=4.5km/h

x-y=4.5

or, x-4.5=y

or, 9-4.5=y

or,y=4.5

Steam of the river is 4.5km/h.