Question

A streamer goes downstream and covers a distance between two ports in 4 hours while it covers the same distance upstream in 5 hours. If the speed of the stream is 2 km/h, find rhe speed of the stream on still water​

Answer 1

Speed of the streamer in still water = x

Speed of stream = 2kmph

Downstream

Speed = x+2

Time = 4 Hours

Distance = d = 4(x+2) (We know that distance = speed * time ) equation 1

Upstream

Speed = x-2 (Syream acts against the boat)

Time = 5 hours

Distance = d = 5(x-2) equation 2

Equating equation 2 and 1 since d=d

Therefore,

5x-10=4x+8

= 5x-10-4x=8

= x = 8+10=18

Therefore x=18 I.e The speed of the boat/streamer in still water is 18kmph