Question

A river is streaming at the speed of . A man rowing his boat in the river took hour more
in covering upstream than covering downstream. The speed of boat in still
water is:

Answer 1

Consider,
Speed of rowing by a person =5 km/hr.
Speed of stream =x km/hr
Upstream Speed =(5−x) km/hr
Downstream speed =(5+x) km/hr
According to the question,
⇒
5−x
40
​
=
5+x
3×40
​


⇒5+x=15−3x

⇒4x=10

⇒x=2.5 km/hr