Question

A man can row 3 km in an hour in still water and he finds that it takes twice the time in rowing down is rowing up the stream the rate of the stream is

Answer 1

Answer:

The rate of stream is 1 km / hr

Step-by-step explanation:

Let the rate of the stream be x km / hr

So,

The upward speed = ( 3 - x ) km/hr

and downward speed = ( 3 + x ) km/hr

Let distance traveled be D, then

Time taken upstream = $\frac{D}{3-x}$

Similarly ,

Time taken downstream = $\frac{D}{3+x}$

According to question,

It takes twice the time in rowing down, that is,

$\frac{D}{3-x}$ = $\frac{2D}{3+x}$

D ( 3 + x ) = 2D ( 3 - x )

Dividing both sides by D,

3 + x = 2 ( 3 - x )

3 + x = 6 - 2x

x + 2x = 6 - 3

3x = 3

x = 3/3

x = 1

Hence,

The rate of stream is 1 km / hr