Question

Лодка плыла 6ч по течению а затем 4ч против течению. Найдите собственную скорость лодки,если известно что скорость течения реки равна 3 км\ч,а всего лодкой пройдено расстояние 126 км Помогите пожалуйста!

Answer 1

Решение на фото))))))))))))))))))))))))))))))

Answer 2

Problem Analysis

We are given that a boat traveled for 6 hours with the current and then 4 hours against the current. The total distance traveled by the boat is 126 km. We also know that the speed of the river current is 3 km/h. We need to find the speed of the boat.

Solution

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

When the boat is traveling with the current, its effective speed is the sum of its own speed and the speed of the current. So, the effective speed is (x + 3) km/h. The boat traveled for 6 hours, so the distance covered is 6 * (x + 3) km.

When the boat is traveling against the current, its effective speed is the difference between its own speed and the speed of the current. So, the effective speed is (x - 3) km/h. The boat traveled for 4 hours, so the distance covered is 4 * (x - 3) km.

According to the problem, the total distance covered by the boat is 126 km. Therefore, we can write the equation:

(6 * (x + 3)) + (4 * (x - 3)) = 126

Simplifying the equation:

6x + 18 + 4x - 12 = 126

10x + 6 = 126

10x = 120

x = 12

Therefore, the speed of the boat in still water is 12 km/h.

Answer

The speed of the boat in still water is 12 km/h.

Explanation

When the boat is traveling with the current, its effective speed is (12 + 3) = 15 km/h. So, in 6 hours, the boat covers a distance of 6 * 15 = 90 km.

When the boat is traveling against the current, its effective speed is (12 - 3) = 9 km/h. So, in 4 hours, the boat covers a distance of 4 * 9 = 36 km.

The total distance covered by the boat is 90 km + 36 km = 126 km, which matches the given information.

Note

Please note that the search results provided by You.com did not provide direct information for this specific problem. However, the solution to this problem is a standard application of the concept of relative speed.