Question

ЗАДАЧАИз пункта M в пункт N со скоростью 4,5км/ч вышел турист. Через 2,5ч. навстречу ему из N выезжает велосипедист, скорость которого 12км/ч. Найдите расстояние MN, если известно, что велосипедист приехал в M одновременно с приходом туриста в N.

Answer 1

Пусть х - искомое расстояние
составляем мат.модель задачи
x/4.5=x/12+2.5
откуда х=18
ответ: MN=18км

Answer 2

Problem Analysis

We are given that a tourist starts from point M and travels towards point N at a speed of 4.5 km/h. After 2.5 hours, a cyclist starts from point N and travels towards point M at a speed of 12 km/h. We need to find the distance between points M and N, given that the cyclist arrives at point M at the same time as the tourist arrives at point N.

Solution

Let's assume the distance between points M and N is d km.

The time taken by the tourist to travel from M to N is given by: time = distance / speed = d / 4.5 hours.

The time taken by the cyclist to travel from N to M is given by: time = distance / speed = d / 12 hours.

According to the problem, the cyclist arrives at point M at the same time as the tourist arrives at point N. Therefore, we can set up the following equation:

d / 4.5 = d / 12

To solve for d, we can cross-multiply and solve the resulting equation.

Calculation

Let's solve the equation to find the value of d:

d / 4.5 = d / 12

Cross-multiplying:

12d = 4.5d

Dividing both sides by 4.5:

12d / 4.5 = d

Simplifying:

2.6667d = d

Dividing both sides by d:

2.6667 = 1

This equation is not possible, as it leads to a contradiction. Therefore, there is no solution to this problem.

Answer

The distance between points M and N cannot be determined based on the given information.