Question

ДВА ПОЕЗДА ИДУТ НА ВСТРЕЧУ ДРУГ ДРУГУ СО СТАНЦИИ ,РАСТОЯНИЕ МЕЖДУ КОТОРЫМИ 385 КМ.ПЕРВЫЙ ПОЕЗД ВЫШЕЛ НА 2 ЧАСА РАНЬШЕ СО СКОРОСТЬЮ 53 КМ В ЧАС.ПОЕЗДА ВСТРЕТИЛИСЬ ЧЕРЕЗ 3 ЧАСА ПОСЛЕ ВЫХОДА ВТОРОГО ПОЕЗДА.НАЙДИ СКОРОСТЬ ВТОРОГО ПОЕЗДА?

Answer 1

Расстояние 385 км.
покзда встретились через 3 часа.
первый выехал на 2 часа раньше чем второй.
второй шёл 3 часа первый шёл 3+2=5(ч)
скорость первого 53км/ч.
за 5 часов он прошёл 53*5=265км
второму надо до встречи пройти
385-265=120км.(как мы знаем,за 3 часа)
значит, он прошёл со скоростью 120:3=40км/ч.
задача прввильная

Answer 2

Problem Analysis

We are given two trains traveling towards each other from different stations. The distance between the stations is 385 km. The first train started 2 hours earlier and has a speed of 53 km/h. The trains meet after 3 hours of the second train's departure. We need to find the speed of the second train.

Solution

Let's assume the speed of the second train is x km/h.

The first train travels for a total of 3 + 2 = 5 hours. The distance traveled by the first train is 53 km/h * 5 h = 265 km.

The remaining distance between the two trains is 385 km - 265 km = 120 km.

Since the two trains are traveling towards each other, the combined speed of the two trains is the sum of their individual speeds.

Therefore, the combined speed of the two trains is 53 km/h + x km/h.

We can use the formula: speed = distance / time to find the time taken by the second train to cover the remaining distance.

The time taken by the second train is 120 km / (53 km/h + x km/h).

According to the problem, the second train takes 3 hours to cover the remaining distance.

So, we can set up the equation: 3 = 120 km / (53 km/h + x km/h).

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

Let's solve the equation:

3 = 120 km / (53 km/h + x km/h)

Multiplying both sides by (53 km/h + x km/h):

3 * (53 km/h + x km/h) = 120 km

159 km/h + 3x km/h = 120 km

Subtracting 159 km/h from both sides:

3x km/h = 120 km - 159 km/h

3x km/h = -39 km

Dividing both sides by 3 km/h:

x km/h = -39 km / 3 km/h

x km/h = -13 km/h

Since speed cannot be negative, we can conclude that there is no valid solution for the speed of the second train.

Therefore, there is no valid speed for the second train that satisfies the given conditions.

Answer

There is no valid speed for the second train that satisfies the given conditions.