A boat takes total 08 hrs. to cover a distance of 25 km in upstream and comes back 39 km in downstream. While it takes 10 hrs. to cover a distance of 30 km in upstream and comes back 52 km in downstream. Find speed of the boat in still water.

09 km/hr

\(\frac{25}{x - y}\) + \(\frac{39}{x + y}\) = 8   ---(i)

\(\frac{30}{x - y}\) + \(\frac{52}{x + y}\) = 10   ---(ii)

(i) x 6 - (ii) x 5 

\(\frac{26}{x + y}\) = 2

x + y = 13

x - y = 5

x=9, y = 4