Question

Два туриста вышли одновременно навстречу друг другу из пунктов, расстояние между которыми равно 18 км. Один из них проходит в час в среднем 4 км, а второй 5 км. Через сколько часов они встретятся?

Answer 1

18/(4+5)=18/9=2 (ч) - через столько они встретятся

Answer 2

18 : ( 4 + 5 ) = 2 ( часа )

Answer 3

Answer in detail. Two tourists left at the same time to meet each other from points, the distance between which is 18 km. One of them passes on average 4 km per hour, and the second 5 km. How many hours will they meet?

To answer this question, we can use the formula for the relative speed of two moving objects:

$$v_r = v_1 + v_2$$

where $v_r$ is the relative speed, $v_1$ is the speed of the first object, and $v_2$ is the speed of the second object.

In this case, the first tourist has a speed of 4 km/h, and the second tourist has a speed of 5 km/h. Therefore, the relative speed of the two tourists is:

$$v_r = 4 + 5 = 9 \text{ km/h}$$

This means that the distance between them decreases by 9 km every hour. Since the initial distance is 18 km, we can find the time it takes for them to meet by dividing the distance by the relative speed:

$$t = \frac{d}{v_r} = \frac{18}{9} = 2 \text{ hours}$$

Therefore, the two tourists will meet after 2 hours.