X and Y are two stations that are 280 km apart. A train starts at a certain time from X and travels towards Y at 60 km/h. After 2 hours, another train starts from Y and travels towards X at 20 km/h After how many hours does the train leaving from X meet the train which left from Y?
1
4 hours
2
3 hours
3
6 hours
4
2 hours