Question

A boat covers a certain distance downstream in 1 hour, while it comes back in 1.5 hours. If the speed of the stream be 3 kmph, what is the speed of the boat in still water ?

Answer 1

Let the speed of the boat in still water be x kmph.

Speed downstream = (x+3) kmph

Speed upstream = (x-3) kmph

Therefore,

$1(x+3)=1.5(x-3)$

$x+3=1.5x-4.5$

$x=15kmph$