Question

Скорый поезд отошел от пункта А в 8 ч 02 мин и двигался со скоростью 79 км/ч. Второй вышел из пункта В на час позже.Его скорость была 72 км/ч .Когда первый поезд прибыл в пункт В второй находился от него на расстоянии 114 км.Определите во сколько первый поезд лостиг пункта В и расстояние между пунктами А и В?

Answer 1

114/72=1 42/72=1 7/12 ч=1 ч 35 мин - время второго
1ч35мин+1ч=2ч35мин - время второго
8ч02мин+2ч35мин=10ч37мин - время прибытия первого в В
2 ч35мин=2 35/60=2 7/12 ч
79*2 7/12=79*31/12=2449/12=204 1/12 км

Answer 2

Problem Analysis

We are given two trains, Train A and Train B, which depart from points A and B, respectively. Train A departs at 8:02 AM and travels at a speed of 79 km/h. Train B departs one hour later and travels at a speed of 72 km/h. When Train A arrives at point B, Train B is 114 km away from it. We need to determine the time it takes for Train A to reach point B and the distance between points A and B.

Solution

Let's start by calculating the time it takes for Train A to reach point B. We can use the formula `time = distance / speed` to calculate the time taken by each train.

The time taken by Train A to reach point B can be calculated as follows: ``` time_A = distance_AB / speed_A ``` where `distance_AB` is the distance between points A and B, and `speed_A` is the speed of Train A.

We are given that Train A travels at a speed of 79 km/h. To calculate the distance between points A and B, we can use the formula `distance = speed * time`. Rearranging the formula, we get: ``` distance_AB = speed_A * time_A ```

Now, let's calculate the time taken by Train B to reach point B. We know that Train B departs one hour later than Train A, so the time taken by Train B is: ``` time_B = time_A - 1 ```

We are given that Train B travels at a speed of 72 km/h. Using the formula `distance = speed * time`, we can calculate the distance between points A and B for Train B: ``` distance_AB = speed_B * time_B ```

Since both trains travel the same distance between points A and B, we can equate the two distance formulas and solve for the distance: ``` speed_A * time_A = speed_B * time_B ```

Substituting the values we have, we get: ``` 79 * time_A = 72 * (time_A - 1) ```

Simplifying the equation, we get: ``` 79 * time_A = 72 * time_A - 72 ```

Solving for `time_A`, we find: ``` time_A = 72 / (79 - 72) = 72 / 7 = 10.2857 hours ```

Therefore, Train A takes approximately 10.2857 hours to reach point B.

To calculate the distance between points A and B, we can substitute the value of `time_A` into the