# A passenger train departed from point A to point B, the distance between which is 600 km.

A passenger train departed from point A to point B, the distance between which is 600 km. At the same time, a freight train departed from point B to point A. Its speed is 10 km / h less than the speed of a passenger train. distance from point A was a freight train an hour after meeting with a passenger?

Let the speed of a passenger train be x km / h, then the speed of a freight train is x – 10 km / h. Since such quantities as time and distance are known, an equation can be drawn up:

1) x + (x-10) x 4 = 600;

2 x – 10 = 600: 4;

2 x – 10 = 150;

2 x = 150 + 10;

2 x = 160;

x = 160: 2;

x = 80 (km / h) – the speed of the passenger train.

2) 80 – 10 = 70 (km / h) – the speed of a freight train.

3) 70 x 4 = 280 (km) – a freight train passed before meeting a passenger train.

Since it is known that a freight train was traveling at a speed of 70 km / h, it covered 280 km before meeting a passenger train, and 1 hour after meeting a passenger train, it passed:

4) 280 + 70 = 350 (km).

5) 600 – 350 = 250 km (km) – the distance at which the freight train was from point A after meeting with the passenger train.