Question

Катер шел по течению реки 5часов а затем против течения 3 часа Найдите собственную скорость катера если известно что скорость течения реки 3 километров час а всего пройдено 126 километров

Answer 1

Пусть собственная скорость катера -х. ⇒
(х+3)*5+(х-3)*3=126
5x+15+3x-9=126
8x=120
x=15.
Ответ: собственная скорость катера 15 км/ч.

Answer 2

Calculation of the Boat's Speed

To find the boat's speed, we need to consider the time it traveled with the current and against the current, as well as the total distance covered.

Given information: - The boat traveled with the current for 5 hours. - The boat traveled against the current for 3 hours. - The speed of the river's current is 3 kilometers per hour. - The total distance covered by the boat is 126 kilometers.

To solve this problem, we can use the formula: distance = speed × time.

Let's denote the boat's speed as x (in kilometers per hour).

1. When the boat is traveling with the current, its effective speed is the sum of its own speed and the speed of the current: (x + 3) kilometers per hour. - The time traveled with the current is 5 hours. - Therefore, the distance traveled with the current is (x + 3) × 5 kilometers.

2. When the boat is traveling against the current, its effective speed is the difference between its own speed and the speed of the current: (x - 3) kilometers per hour. - The time traveled against the current is 3 hours. - Therefore, the distance traveled against the current is (x - 3) × 3 kilometers.

The total distance covered by the boat is given as 126 kilometers.

Using the above information, we can set up the equation:

(x + 3) × 5 + (x - 3) × 3 = 126

Now, let's solve this equation to find the boat's speed.

Solving the Equation

Expanding the equation:

5x + 15 + 3x - 9 = 126

Combining like terms:

8x + 6 = 126

Subtracting 6 from both sides:

8x = 120

Dividing both sides by 8:

x = 15

Therefore, the boat's speed is 15 kilometers per hour.

Conclusion

The boat's speed is 15 kilometers per hour.