The speed of the train is 60 km/h. Speed is calculated by dividing the distance by the time:

Speed=DistanceTime=120 km2 hours=60 km/h\text{Speed}=\frac{\text{Distance}}{\text{Time}}=\frac{120\text{ km}}{2\text{ hours}}=60\text{ km/h}Speed=TimeDistance​=2 hours120 km​=60 km/h