#TSD-2

How much time will an express train of length 150 meters and running at a speed of 75 kmph take to cross a man walking at 5 m/s inside a passenger train of length 200 meters and running at 15 kmph in a direction opposite to that of the express train. The man is walking inside the train and in opposite direction to that of the train. (Assume the man does not reach the end of his train meanwhile.)

Solution-

Speed of man with respect to passenger train = 5m/sec  or 18km/hr
Speed of man with respect to ground = 18 - 15 = 3km/hr

Speed of man with respect to express train = 75 - 3 = 72 km/hr or 20m/sec

Time taken by express train to cross man = 150/20 = 7.5 sec ANS

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