The train left the station at a speed of 50 km / h; 3 hours later a second train followed him

The train left the station at a speed of 50 km / h; 3 hours later a second train followed him at a speed of 80 km / h. How long will it take for them to meet?

Let’s solve this task by actions with explanations:
1) 50 * 3 = 150 kilometers – the distance traveled by the first train at a speed of 50 kilometers per hour 3 hours before the departure of the second train at a speed of 80 kilometers per hour;
2) 80 – 50 = 30 kilometers per hour – the speed of convergence of two trains, as they move one after the other;
3) 150: 30 = 5 hours – after this time the trains will meet.
Answer: in 5 hours.