Question

Расстояние между поездами, идущими навстречу друг другу, равно 300км. Через 1,5 часа оно сократилось до 90 км. Найдите скорости поездов, если у одного из них скорость в 1+1/3 раза больше.

Answer 1

Пошаговое объяснение:

1) S =  300 - 90 = 210 км -  пройденный путь.

2) Vc = S/t = 210 : 1.5 = 140 км/ч - скорость сближения - сумма скоростей.

3) 1 + 1 1/3 = 2 1/3 = 7/3 =  - делим на части.

4) 140 : 7/3 =  20*3 = 60 км/ч - скорость первого - ответ.

5) 140 - 60 = 80 км/ч - скорость второго - ответ

5а) 60 * 4/3 = 80 км/ч

Answer 2

Problem Analysis

We are given that two trains are traveling towards each other, and the distance between them is initially 300 km. After 1.5 hours, the distance between them has reduced to 90 km. We need to find the speeds of the trains, given that one train's speed is 1 1/3 times greater than the other.

Solution

Let's assume the speed of the slower train is x km/h. Then, the speed of the faster train is (4/3)x km/h, as it is 1 1/3 times greater.

We can use the formula distance = speed × time to solve this problem.

After 1.5 hours, the slower train has traveled a distance of 1.5x km, and the faster train has traveled a distance of (4/3)x × 1.5 km.

According to the problem, the total distance between the trains has reduced from 300 km to 90 km. Therefore, we can set up the following equation:

300 - (1.5x + (4/3)x × 1.5) = 90

Simplifying the equation:

300 - (1.5x + 2x) = 90

300 - 3.5x = 90

3.5x = 210

x = 60

Therefore, the speed of the slower train is 60 km/h, and the speed of the faster train is (4/3) × 60 = 80 km/h.