If two train of length a metres and b metres are moving in opposite direction at u m/s and v m/s: then time taken by trains to cross each other.

If two trains of length a metres and n metres are moving in the same direction at u m/s and vm/s: then time taken by faster train to cross the slower train.

L_(1) metre train is moving with a velocity of v_(1) m/s and another L_(2) metre train is moving with a velocity of v_(2) m/s in opposite direction. Find out The time taken by two train to cross each other

A train A which is 120 m long is running with velocity 20 m/s while train B which is 130 m long is running in opposite direction with velocity 30 m/s. What is the time taken by train B to cross the train A?