Question

Question #86905

Answer 1

15 kmph

Explanation:

Let the speed of the boat = x kmph.

In down stream in 1 hour boat goes = sp. of the boat + sp of the stream = x+3 km.

In upstream, same distance goes by 1 1/2 hours. So in 1 1/2 it travels = (sp. of the boat - sp. of the stream) x 3/2 = (x-3)3/2 km.

Hence, `(x-3). 3/2 = x+3`
`rArr 3x-9=2x+6`
`rArr 3x-2x = 6+9`
`rArr x = 15`