The own speed of the motor boat is 12.6 km / h, and the speed of the river is 1.8 km / h.

The own speed of the motor boat is 12.6 km / h, and the speed of the river is 1.8 km / h. Which way the boat will go upstream and against the current in 2.5 hours.

1. Let’s calculate how far the boat will go downstream in 2.5 hours, multiplying this time by the sum of its own speed and the speed of the river flow:
2.5 * (12.6 + 1.8) = 2.5 * 14.4 = 36 km.
2. Now let’s determine the path that the boat will sail against the current in 2.5 hours. To do this, we multiply this time by the difference between its own speed and the speed of the current, we get:
2.5 * (12.6 – 1.8) = 2.5 * 10.8 = 27 km.
Answer: the boat will sail 36 km downstream or 27 km upstream in 2.5 hours.