The distance between the cities is located on the banks of one river 720 km, the ship moving downstream overcomes in 36

The distance between the cities is located on the banks of one river 720 km, the ship moving downstream overcomes in 36 hours and 45 hours against the current, find your own speed of the boat.

Task on the topic: speed, time, distance. It is calculated by the formula: S = v * t, where v – speed, t – time, S – distance.
Given:
v sob =? km / h;
t 1 = 36 hours; t 2 = 45 hours;
S = 720 km.

Let’s find the speed of the boat downstream:
1) 720: 36 = 20 (km / h);

Let’s calculate the speed of the boat against the current:

2) 720: 45 = 16 (km / h);

Let’s calculate the speed of the river flow:

3) (20 – 16): 2 = 2 (km / h);

Thus, the boat’s own speed:

4) 20 – 2 = 18 (km / h).

Answer: 18 km / h. own speed of the boat.