Question

два поїзди вийшли одночасно назустріч один одному.Перший поїзд рухався зі швидкістю 72км/г,другий 68км/г.Другий поїзд до зустрічі пройшов 408 км.Яку відстань пройшов перший поїзд?

Answer 1

1)408:68=6 год рухалися поїзда до зустрічи

2)72*6=432 км пройшов перший поїзд

====================================================

Answer 2

Problem Analysis

We are given that two trains start simultaneously and move towards each other. The first train has a speed of 72 km/h, while the second train has a speed of 68 km/h. We are also given that the second train has traveled a distance of 408 km before they meet. We need to find the distance traveled by the first train.

Solution

Let's assume that the distance traveled by the first train is x km.

Since both trains are moving towards each other, the sum of the distances traveled by both trains will be equal to the total distance between them when they meet.

According to the problem, the second train has traveled a distance of 408 km. So, the distance traveled by the first train (x) and the distance traveled by the second train (408 km) will add up to the total distance between them.

Therefore, we can write the equation:

x + 408 = total distance

To find the total distance, we need to calculate the time it takes for the trains to meet. We can use the formula:

time = distance / speed

The time taken by the first train to meet the second train will be the same as the time taken by the second train to meet the first train.

Let's calculate the time taken by the first train:

time taken by first train = x / 72

And the time taken by the second train:

time taken by second train = 408 / 68

Since both times are equal, we can equate them:

x / 72 = 408 / 68

Now, we can solve this equation to find the value of x.

Calculation

Let's solve the equation:

x / 72 = 408 / 68

Cross-multiplying:

68x = 72 * 408

Dividing both sides by 68:

x = (72 * 408) / 68

Calculating the value of x:

x = 432

Answer

Therefore, the first train has traveled a distance of 432 km.

Explanation

When the two trains meet, the first train has traveled 432 km, while the second train has traveled 408 km. The total distance between them is the sum of these distances, which is 840 km.