Question

Катер по течению за 3 ч. проплыл такое же расстояние, которое проплывает за 5 ч. против течения. Скорость течения реки равна 2 км/ч. Вычисли скорость катера в стоячей воде.

Answer 1

(х-2)*5=(х+2)*3
5х-10=3х+6
2х=16
х=8
Ответ: 8 км/ч

Answer 2

3(x+2)=(x-2)5
3x+6=5x-10
2x=16
x=8
X= скорость 

Answer 3

Problem Analysis

We are given that a boat traveled the same distance in 3 hours downstream (with the current) as it did in 5 hours upstream (against the current). The speed of the river current is given as 2 km/h. We need to calculate the speed of the boat in still water.

Solution

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

When the boat is traveling downstream, its effective speed is the sum of its speed in still water and the speed of the current. Therefore, the boat's effective speed downstream is (x + 2) km/h.

When the boat is traveling upstream, its effective speed is the difference between its speed in still water and the speed of the current. Therefore, the boat's effective speed upstream is (x - 2) km/h.

We are given that the boat traveled the same distance downstream in 3 hours as it did upstream in 5 hours. Using the formula distance = speed × time, we can set up the following equation:

(x + 2) × 3 = (x - 2) × 5

Simplifying the equation:

3x + 6 = 5x - 10

6 + 10 = 5x - 3x

16 = 2x

x = 8

Therefore, the speed of the boat in still water is 8 km/h.

Answer

The speed of the boat in still water is 8 km/h.