Question

Моторная лодка шла 4 часа по течению и 5 часов против течения.Путь пройденный лодкой против течения на 8,3 км длиннее чем путь пройденный по течению . Найдите путь пройденный по течению ,если скорость течения реки равна 1,3 км ч .Напишите с уравнением

Answer 1

4 * ( X + 1,3 ) + 8,3 = 5 * ( X - 1,3 ) 
4X + 5,2 + 8,3 = 5X - 6,5 
5X - 4X = 13,5 + 6,5 
X = 20 (  км/час ) собственная скорость лодки
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4 * ( 20 + 1,3 ) = 4 * 21,3 = 85,2 ( км )
ОТВЕТ 85,2 км 

Answer 2

Problem Analysis

We are given that a motorboat traveled for 4 hours with the current and 5 hours against the current. The distance traveled against the current is 8.3 km longer than the distance traveled with the current. We need to find the distance traveled with the current, given that the speed of the current is 1.3 km/h.

Solution

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

When the motorboat is traveling with the current, its effective speed is the sum of its speed in still water and the speed of the current. Therefore, the distance traveled with the current can be calculated as:

Distance with current = (Speed with current) x (Time with current)

Similarly, when the motorboat is traveling against the current, its effective speed is the difference between its speed in still water and the speed of the current. Therefore, the distance traveled against the current can be calculated as:

Distance against current = (Speed against current) x (Time against current)

Given that the distance traveled against the current is 8.3 km longer than the distance traveled with the current, we can write the following equation:

Distance against current = Distance with current + 8.3

Now, let's substitute the values we have:

Distance against current = (x - 1.3) x 5

Distance with current = (x + 1.3) x 4

Substituting these values into the equation above, we get:

(x - 1.3) x 5 = (x + 1.3) x 4 + 8.3

Simplifying this equation will give us the value of x, which represents the speed of the motorboat in still water.