GIVEN: Lengths of trains = 160 m and 120 m Speeds of trains = 72 km/h and 54 km/h FORMULA USED: Relative speed = (a + b) for opposite directions Where, a and b are speeds of train Speed = Distance/Time CALCULATION: Trains are travelling in the opposite directions Relative speed of 2 trains = 72 + 54 = 126 km/h = 126 km/hr Relative speed of 2 trains =126×
5
18
=35 m/s Total distance to cover =160+120=280 m ∴ Required time to cross each other = 280/35 = 8 seconds