Question

От станции A до станции B поезд проехал за 1,5 часа. От станции B до станции A электричка проехала за 2,4 часа. Известно, что электричка шла на 30 км/ч медленнее, чем поезд. Определи скорость поезда и скорость электрички. Ответ: скорость электрички — км/ч; скорость поезда — км/ч.

Answer 1

Ответ:

Объяснение:

Пусть х км/ч - скорость электрички, тогда скорость поезда х+30 км/ч. Известно, что поезд прошел путь за 1,5 ч,, а электричка за 2,4 ч. Составим уравнение:

х*2,4=(х+30)*1,5

2,4х=1,5х+45

2,4х-1,5х=45

0,9х=45

х=45:0,9

х=50 (км/ч) - скорость электрички

50+30=80 (км/ч) - скорость поезда

Answer 2

Problem Analysis

We are given that a train traveled from station A to station B in 1.5 hours, and an electric train traveled from station B to station A in 2.4 hours. We also know that the electric train was 30 km/h slower than the regular train. We need to determine the speed of the regular train and the speed of the electric train.

Solution

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

To solve this problem, we can use the formula:

distance = speed × time

We can set up two equations using this formula, one for the regular train and one for the electric train.

For the regular train: distance_AB = x × 1.5

For the electric train: distance_BA = (x - 30) × 2.4

Since the distance from A to B is the same as the distance from B to A, we can set these two equations equal to each other:

x × 1.5 = (x - 30) × 2.4

Now we can solve this equation to find the value of x, which represents the speed of the regular train.

Calculation

Let's solve the equation:

x × 1.5 = (x - 30) × 2.4

Expanding the equation:

1.5x = 2.4x - 72

Rearranging the equation:

2.4x - 1.5x = 72

Simplifying:

0.9x = 72

Dividing both sides by 0.9:

x = 80

The speed of the regular train is 80 km/h.

Since the speed of the electric train is 30 km/h slower, its speed will be:

80 - 30 = 50 km/h

The speed of the electric train is 50 km/h.

Answer

The speed of the regular train is 80 km/h and the speed of the electric train is 50 km/h.