Question

A motor boat whose speed is 18 km/hr in still water takes 1hr more to go 24 km upstream then to return downstream in the same part . Find the speed of the stream

Answer 1

upstream means stream is supporting boat in its motion while opposing it in downstream motion.

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 .