Question

Почтовый поезд прошел расстояние между двумя городами за 8 ,ч со скоростью 60км /ч. За сколько часов пройдет это рассточние скорый поезд, если его скорость на 20 км/ч больше скорости почтового поезда?

Answer 1

Скорость скорого поезда = 60 км/ч + 20 км/ч= 80 км/ч
Пусть время, за которое пройдет скорый поезд - х часов.
Так как у  этих поездов расстояние одинаковое, то составим и решим уравнение:
60*8=80х
480=80х
х=480/80
х=6
Ответ: скорый поезд пройдет это расстояние за 6 часов.

Answer 2

Calculation of Time for the Express Train to Cover the Distance

To calculate the time it takes for the express train to cover the distance between the two cities, we need to consider the speed of the express train and the speed of the mail train.

Given: - The mail train covers the distance at a speed of 60 km/h. - The express train's speed is 20 km/h faster than the mail train.

To find the time it takes for the express train to cover the distance, we can use the formula:

Time = Distance / Speed

Let's calculate the time it takes for the mail train to cover the distance first.

Distance = Speed * Time

Since the mail train covers the distance at a speed of 60 km/h, and it takes 8 hours to cover the distance, we can calculate the distance as follows:

Distance = 60 km/h * 8 hours = 480 km

Now, let's calculate the time it takes for the express train to cover the same distance.

The express train's speed is 20 km/h faster than the mail train, so its speed is 60 km/h + 20 km/h = 80 km/h.

Using the formula mentioned earlier, we can calculate the time it takes for the express train to cover the distance:

Time = Distance / Speed = 480 km / 80 km/h = 6 hours

Therefore, the express train will cover the distance in 6 hours.

Answer

The express train will cover the distance between the two cities in 6 hours if its speed is 20 km/h faster than the mail train's speed.