# The boat passed 80 km less in 3.5 hours than the motor ship in 4 hours. The speed of the boat is 15

**The boat passed 80 km less in 3.5 hours than the motor ship in 4 hours. The speed of the boat is 15 km / h less than the speed of the motor ship. Find the speed of the motor ship and the speed of the boat.**

Let us denote by variable x the speed with which this boat is moving.

Therefore, according to the condition of the problem, we can express the speed of the ship in terms of (x + 15).

Knowing that the boat covered the distance 80 kilometers less in 3.5 hours of sailing than the distance covered by the motor ship in 4 hours of sailing, we will compose an equation and determine the speed of the boat and the speed of the motor ship:

3.5x + 80 = 4 (x +15);

0.5x = 20;

x = 40;

40 + 15 = 55.

Answer: The speed of the boat is 40 km / h, and the speed of the motor ship is 55 km / h.