Answer :

Solution :

Speed of the train = 54 km/h = 15 m/s S

peed of a man = 9 km/h = 2.5 m/s

Relative speed of the train with respect to man = 15 – 2.5 = 12.5 m/s

Train takes 14 seconds to pass the man.

In these 14 seconds, the distance covered by the train is nothing but the length of the train.

Length of the train = speed × time = 12.5 × 14 = 175 m

From the time the front of a train enters a platform, it takes 25 seconds for the back of the train to leave the platform.

In these 25 seconds, the distance covered by the train is nothing but the sum of length of the train and the length of the platform.

Length of the train + Length of platform = 15 × 25 = 375 m

Now, length of the platform = 375 – 175 = 200 m