Question

Из двух городов навстречу друг другу одновременно отправились два поезда. Скорость одного 60 км/ч, другой за 1 час проходит на 20 км больше. Через 3ч 30мин поезда встретились. Найди расстояние между городами.

Answer 1

60+20=80 (км/ч) - скорость 2 поезда

60+80=140 (км/ч) - скорость сближения поездов

3ч30 мин= 3,5 ч

140*3,5=490 (км)- расстояние между городами

Answer 2

Problem Analysis

We are given that two trains start simultaneously from two different cities and meet after 3 hours and 30 minutes. The speed of one train is 60 km/h, while the other train covers 20 km more in 1 hour. We need to find the distance between the two cities.

Solution

Let's assume the speed of the second train is v km/h. According to the problem, the second train covers 20 km more than the first train in 1 hour. So, we can write the equation:

v - 60 = 20

Simplifying the equation, we get:

v = 80

Now, we can calculate the distance between the two cities using the formula:

Distance = Speed * Time

For the first train, the distance covered in 3 hours and 30 minutes (or 3.5 hours) is:

Distance1 = 60 * 3.5

For the second train, the distance covered in 3 hours and 30 minutes is:

Distance2 = 80 * 3.5

Adding the distances covered by both trains will give us the total distance between the two cities:

Total Distance = Distance1 + Distance2

Let's calculate the total distance:

Total Distance = (60 * 3.5) + (80 * 3.5)

Calculation

Total Distance = (60 * 3.5) + (80 * 3.5) Total Distance = 210 + 280 Total Distance = 490 km

Answer

The distance between the two cities is 490 km.

Explanation

Two trains start simultaneously from two different cities. The first train has a speed of 60 km/h, while the second train has a speed of 80 km/h. The second train covers 20 km more than the first train in 1 hour. After 3 hours and 30 minutes, the trains meet. By calculating the distances covered by both trains and adding them together, we find that the total distance between the two cities is 490 km.