Question

Поезд проехал расстояние между двумя городами со скоростью 80 км/ч. Если скорость поезда будет на 20км/ч меньше, то его время в пути стане на 1ч больше. Найди расстояние между городами.

Answer 1

20:2=10,значит на 2 часа 1*8=8(ч),10*8=80(км)

Answer 2

Calculation of Distance between Two Cities

To find the distance between two cities, we can use the given information about the speed of the train and the time difference when the speed is reduced.

Let's assume the original speed of the train is 80 km/h. When the speed is reduced by 20 km/h, the time taken for the journey increases by 1 hour.

To calculate the distance between the two cities, we can use the formula:

Distance = Speed × Time

Let's denote the distance between the two cities as D.

When the speed is 80 km/h, the time taken for the journey is T hours.

Therefore, the distance D can be calculated as:

D = 80 × T When the speed is reduced by 20 km/h, the time taken for the journey increases by 1 hour. So the new time taken for the journey is T + 1 hours.

Therefore, the distance D can also be calculated as:

D = 60 × (T + 1) Now we can equate the two expressions for D and solve for T.

80 × T = 60 × (T + 1)

Simplifying the equation:

80T = 60T + 60

20T = 60

T = 3

Now that we have the value of T, we can substitute it back into either of the expressions for D to find the distance between the two cities.

Using the first expression:

D = 80 × T = 80 × 3 = 240 km

Therefore, the distance between the two cities is 240 km.

Answer

The distance between the two cities is 240 km.