Question

из двух городов одновременно навстречу друг другу выехали два автомобиля и встретились через 3 часа первый автомобиль ехал со скоростью 78 км в час скорость второго автомобиля составляет 9/13 скорости первого. найдите расстояние между городами ( решите по действиям) ​

Answer 1

Ответ:

Пошаговое объяснение:

1) 78 * 9/13 = 6 * 9/1 = 54/1 = 54 (км/ч) - скорость второго

2) 78 + 54 = 132 (км/ч) - скорость сближения

3) 132 * 3 = 396 (км) - расстояние между городами

Ответ: 396 км

Answer 2

Problem Analysis

Two cars are traveling towards each other from two different cities and meet after 3 hours. The first car is traveling at a speed of 78 km/h, while the speed of the second car is 9/13 of the speed of the first car. We need to find the distance between the two cities.

Solution

Let's break down the problem step by step:

1. Let's assume the distance between the two cities is D km. 2. The first car is traveling at a speed of 78 km/h, so in 3 hours, it will cover a distance of 78 km/h * 3 h = 234 km. 3. The second car is traveling at a speed of 9/13 * 78 km/h = 54 km/h (rounded to the nearest whole number). 4. In 3 hours, the second car will cover a distance of 54 km/h * 3 h = 162 km. 5. The total distance covered by both cars is 234 km + 162 km = 396 km. 6. Since the two cars are traveling towards each other, the sum of the distances covered by both cars should be equal to the distance between the two cities. 7. Therefore, we can set up the equation: D = 396 km.

Answer

The distance between the two cities is 396 km.

Verification

Let's verify the answer using the given information and calculations:

- The first car travels at a speed of 78 km/h for 3 hours, covering a distance of 78 km/h * 3 h = 234 km. - The second car travels at a speed of 54 km/h for 3 hours, covering a distance of 54 km/h * 3 h = 162 km. - The sum of the distances covered by both cars is 234 km + 162 km = 396 km, which matches our answer.

Therefore, the answer is verified.

Conclusion

The distance between the two cities is 396 km.