Question

A boatman can row 3 km/h in still water. He takes thrice as much time to row upstream as to row downstream for the same distance. Find speed of water.

Answer 1

here your answer...

time upstream:downstream=3:1

Speed is inversely proportional to time for a given distance and therefore,

speed upstream : speed downstream

=1:3

let the speed of upstream x

speed of downstream 3x

speed in still water

1/2(x+3x)=4x/2

ATQ

4x/2=3

x=3/2=1.5

speed of upstream=1.5

lly downstream=3×1.5=4.5

Rate of stream.

(4.5-1.5)/2=3/2=1.5 kmph