Problems on Trains

2

A train 125 m long passes a man, running at 5 km/hr in the same direction in which the train is going, in 10 seconds. The speed of the train is:

3

The length of the bridge, which a train 130 metres long and travelling at 45 km/hr can cross in 30 seconds, is:

4

Two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and they cross each other in 23 seconds. The ratio of their speeds is: