Question

За три часа движения против течения реки теплоход прошёл на 8 км больше чем за 2 часа движения по течению.Скорость течения реки по течению 2 км в час.Найдите скорость теплохода в стоячей воде.

Answer 1

1) 8- 2 =6 за 2 
2) 8- 6= 2 разница между временем 
3) 2:2 = 1км/ч

Answer 2

Problem Analysis

We are given the following information: - The boat travels 8 km more in 3 hours against the current than it does in 2 hours with the current. - The speed of the current is 2 km/h.

We need to find the speed of the boat in still water.

Solution

Let's assume the speed of the boat in still water is v km/h.

When the boat is moving against the current, its effective speed is reduced by the speed of the current. So, the boat's speed against the current is v - 2 km/h.

When the boat is moving with the current, its effective speed is increased by the speed of the current. So, the boat's speed with the current is v + 2 km/h.

According to the given information, the boat travels 8 km more in 3 hours against the current than it does in 2 hours with the current. We can set up the following equation:

(v - 2) * 3 = (v + 2) * 2 + 8

Let's solve this equation to find the value of v.

Calculation

Expanding the equation, we get:

3v - 6 = 2v + 4 + 8

Simplifying further:

3v - 6 = 2v + 12

Subtracting 2v from both sides:

v - 6 = 12

Adding 6 to both sides:

v = 18

Answer

The speed of the boat in still water is 18 km/h.