Question

Из двух городов,расстояние между которыми равно 420 км,вышли одновременно навстречу друг другу поезда.Встреча произошла через 3 часа.Скорость первого поезда 72км/ч.С какой скоростью шел второй поезд?

Answer 1

Решение:
1)3×72=216 (км) -проехал 1-ый поезд
2)420-216=204 (км) -проехал 2-ой поезд
3)204:3=68 (км\ч) - скорость 2-го поезда
Ответ:68 км\ч

Answer 2

Problem Analysis

We have two trains traveling towards each other from two different cities. The distance between the cities is 420 km. The first train is traveling at a speed of 72 km/h. We need to find the speed of the second train.

Solution

To find the speed of the second train, we can use the formula:

Speed = Distance / Time

Let's calculate the time it took for the trains to meet. We know that the distance between the cities is 420 km and the first train is traveling at a speed of 72 km/h. We can use the formula:

Time = Distance / Speed

Substituting the values, we get:

Time = 420 km / 72 km/h

Calculating this, we find that the time taken for the trains to meet is approximately 5.83 hours.

Now, we can find the speed of the second train using the formula:

Speed = Distance / Time

Substituting the values, we get:

Speed = 420 km / 5.83 hours

Calculating this, we find that the speed of the second train is approximately 72 km/h.

Therefore, the second train is also traveling at a speed of 72 km/h.

Answer

The second train is traveling at a speed of 72 km/h.