Question

CBSE 2018....4 marks....
A motor boat travels with a speed of 18km/he in still water and takes 1 hr more to cover 24km upstream and than to return downstream at the same spot.
Find the speed of stream.

Answer 1

Hey! Answer is 6 km/hr.

Answer 2

Answer:

Let the speed of stream be x km / hr

For upstream = ( 18 - x ) km / hr

For downstream = ( 18 + x ) km / hr

A.T.Q.

24 / 18 - x - 24 / 18 + x = 1

48 x = 324 - x²

x² + 48 x - 324 = 0

( x + 54 ) ( x - 6 ) = 0

x = - 54 or x = 6

Since speed can't be negative .

Therefore , speed of the stream is 6 km / hr .