Question

Два автобуса вышли в разное время навстречу друг другу из двух городов,расстояние между которыми 480км. Скорость первого автобуса 52км/ч,а скорость второго 42км/ч. Пройдя 312км,первый автобус встретился со вторым. На сколько часов первый автобус вышел раньше второго?

Answer 1

сначала найдем сколько первый автобус был в пути,пройдя 312км

312:52=6(ч)-был в пути до встречи

найдем какое расстояние прошел второй до встречи

480-312=168(км)

теперь узнаем сколько был в пути второй автобус

168:42=4(ч)

и найдем на сколько первый вышел раньше второго

6-4=2(ч)

Ответ: на 2 часа раньше 

Answer 2

312:52=6часов первый автобус до встречи со вторым

480-312=168км прошёл 2 ой автобус

168:42=4Ч до встречи

6-4=2ч первый автобус вышел раньше

Answer 3

Problem Analysis

We have two buses that start from different cities and travel towards each other. The distance between the cities is 480 km. The first bus has a speed of 52 km/h, and the second bus has a speed of 42 km/h. After traveling 312 km, the first bus meets the second bus. We need to determine how many hours the first bus left before the second bus.

Solution

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

Let's calculate the time it took for the first bus to travel 312 km: - Time taken by the first bus = 312 km / 52 km/h = 6 hours.

Since the first bus and the second bus meet after 6 hours, we can subtract this time from the total time it would take for both buses to cover the entire distance between the cities.

Let's calculate the total time it would take for both buses to cover the entire distance: - Time taken by both buses = 480 km / (52 km/h + 42 km/h) = 480 km / 94 km/h = 5.1064 hours.

Now, we can calculate the time difference between the total time and the time taken by the first bus: - Time difference = Total time - Time taken by the first bus = 5.1064 hours - 6 hours = -0.8936 hours.

Since the time difference is negative, it means that the first bus left 0.8936 hours (approximately 53.6 minutes) after the second bus.

Therefore, the first bus left approximately 53.6 minutes later than the second bus.

Answer

The first bus left approximately 53.6 minutes after the second bus.