A boat covers 25 km upstream and 44 km downstream in 9 hours also it covers 15 km upstream and 22 km downstream in 5 hours. Find the speed of the boat in still water and that of the stream.

Let the speed of the boat in still water and speed of stream be a km/hr & b km/hr respectively.

In case of upstream;

Speed = speed of boat – speed of stream = a – b

In case of downstream;

Speed = speed of boat + speed of stream = a + b

As, distance = speed x time,

According to the question,

Eqn (i) – 2 × eqn (ii)

⇒ a – b = 5 ...... (iii)

Putting this in equation (i);

⇒ a + b = 11 ...... (iv)

Now solving equation (iii)&(iv) by adding:

2a = 16

a = 8

b = 3.

So, the speed of the boat in still water is 8 km/hr

and the speed of the stream is 3 km/hr.