Question

От станции а до станции б поезд проехал за 1,2 часа. От станции б до станции а электричка проехала за 2,1. Известно, что электричка на 30 км/ч медленнее, чем поезд. Найди скорость поезда и скорость электрички.

Answer 1

Ответ:

Скорость электрички 44 км/ч

Пошаговое объяснение:

Скорость поезда принимаю за "п". Скорость электрички равна "п - 33".

Составлю уравнение:

х(2,1 - 1,2) = 33*2,1. вычисляю:

0,9х = 69,3. Разделю обе части уравнения на 0,9:

х = 69,3/0,9 = 77 км/час. Это скорость поезда.

77 - 33 = 44 км/час. Это скорость электрички.

Answer 2

Problem Analysis

We are given the following information: - The train traveled from station A to station B in 1.2 hours. - The train traveled from station B to station A in 2.1 hours. - The train is 30 km/h faster than the electric train.

We need to find the speeds of both the train and the electric train.

Solution

Let's assume the speed of the train is x km/h. Since the electric train is 30 km/h slower, its speed will be (x - 30) km/h.

To find the speeds, we can use the formula: speed = distance / time.

Let's calculate the distances traveled by both trains.

The train traveled from station A to station B in 1.2 hours, so the distance is 1.2x km.

The train traveled from station B to station A in 2.1 hours, so the distance is 2.1x km.

Now we can set up the following equations:

1.2x = distance from A to B 2.1x = distance from B to A

Let's solve these equations to find the values of x and (x - 30).

Calculation

Equation 1: 1.2x = distance from A to B Equation 2: 2.1x = distance from B to A

We can solve these equations simultaneously to find the values of x and (x - 30).

Multiplying Equation 1 by 2.1 and Equation 2 by 1.2, we get:

2.52x = distance from A to B 2.52x = distance from B to A

Since the distances are the same, we can equate them:

2.52x = 2.52x

Now we can solve for x:

2.52x - 2.52x = 0 0 = 0

Since the equation is true for any value of x, it means that there are infinitely many solutions. This means that we cannot determine the exact speeds of the train and the electric train with the given information.

However, we can express the speeds in terms of x:

The speed of the train is x km/h. The speed of the electric train is (x - 30) km/h.

Therefore, the speeds of the train and the electric train cannot be determined uniquely with the given information, but they can be expressed in terms of x.

Answer

The speed of the train is x km/h, and the speed of the electric train is (x - 30) km/h. However, the exact values of x and (x - 30) cannot be determined with the given information.

Please let me know if there's anything else I can help you with!