The speed of boat in still water is 6 km/h more than the speed of current.  If a boat takes total 8 hours to cover 44 km in downstream and 36 km in upstream, find the speed of current (in km/h).

8

Let, speed of boat = x, speed of current = y

x - y = 6 km/h

\(\frac{44}{x + y}\) + \(\frac{36}{x - y}\) = 8

⇒ \(\frac{44}{x + y}\) + \(\frac{36}{6}\) = 8

⇒ \(\frac{44}{x + y}\) = 2 ⇒ x + y = 22

x + y = 22

x - y = 6

2x = 28

 x = 14            y = 22 - 14 = 8 km/h