The boat, whose own speed is 22 km / h, crossed the river in 1 hour 15 minutes the same distance as in 1 hour 30 minutes

The boat, whose own speed is 22 km / h, crossed the river in 1 hour 15 minutes the same distance as in 1 hour 30 minutes against the current. Find the speed of the current.

Let x (km / h) be the speed of the river
The distance that the boat has sailed is the same.
22 + x (km / h) – speed along the river
22-x (km / h) – speed against the river flow
1h 15min = 1.25h
1h 30min = 1.5h
Let’s make the equation:
(22 + x) * 1.25 = (22-x) * 1.5
27.5 + 1.25x = 33-1.5x
2.75x = 5.5
x = 2
This means that 2 km / h is the speed of the river
Answer: 2 km / h