A boat takes 11 hours to travel a distance upstream and takes 5 hours to travel the same distance downstream. If the speed of the boat in still water is $$2 \frac {2}{9}\text{m/s}$$ then, the speed of the stream (in km/h) is:

Correct option is B

Given:
Upstream time 11 h and downstream time 5 hrs.
The speed = 2 $$\frac 29$$​
Solution:
2 $$\frac 29$$m/sec = 20/9 × 18/5= 8 km/h
Upstream speed = 8 − x km/h
Downstream speed = 8 + x km/h
Let the speed of the stream is x km/h
As per the question,
=> 11 ( 8 - x) = 5 (8 + x)
=> 16 x = 48
=> x = 3 km/h