Question

Автомобиль приезжает расстояние между пунктами А и В за 7,2 ,а автобус 0,25 этого расстояния за 3 часа.Через какое время встретятся автомобиль и автобус,если одновременно выйдут из пунктов А и В навстречу друг другу ?

Answer 1

3/0.25=12
1/(1/12+1/7.2)=4½

Answer 2

Решение:
Скорость автомобиля при расстоянии (S) от пункта А до пункта В равна:
V=S/7,2
Скорость автобуса равна:
V=S/0,25 : 3=S/4:3=S/12
Скорость сближения автомобиля и автобуса равна:
S/7,2+S/12=(S+0,6*S)/7,2=1,6S/7,2=S/4,5=2S/9
Автомобиль и автобус встретятся через:
S : 2S/9=S*9/2S=4,5 (часа)

Ответ: Автомобиль и автобус встретятся через 4,5часа

Answer 3

Problem Analysis

We are given that a car travels a distance between points A and B in 7.2 hours, while a bus covers 0.25 of that distance in 3 hours. We need to determine when the car and the bus will meet if they start simultaneously from points A and B and travel towards each other.

Solution

Let's assume that the distance between points A and B is d.

The car travels the entire distance in 7.2 hours, so its speed is d/7.2.

The bus covers 0.25 of the distance in 3 hours, so its speed is (0.25d)/3.

When the car and the bus are traveling towards each other, their speeds are additive. Therefore, the relative speed between the car and the bus is (d/7.2) + ((0.25d)/3).

To find the time it takes for the car and the bus to meet, we can use the formula:

Time = Distance / Speed

Let's calculate the time it takes for the car and the bus to meet:

Time = d / ((d/7.2) + ((0.25d)/3))

Simplifying the equation:

Time = d / ((d/7.2) + (0.0833d))

Time = d / (d/7.2 + 0.0833d)

Time = d / (1.0833d/7.2)

Time = (7.2d) / (1.0833d)

Time = 7.2 / 1.0833

Time ≈ 6.65 hours

Therefore, the car and the bus will meet approximately 6.65 hours after they start from points A and B.

Answer

The car and the bus will meet approximately 6.65 hours after they start from points A and B.