Question

A person rowing a boat at the rate of 5 km/h in still water, takes thrice as much time in going 40 km upstream as in going 40 km downstream. Find the speed of the boat in the still water and the speed of the stream.​

Answer 1

Answer:

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