A train passes a 50 metres long platform in 14 seconds and a man standing on the platform in 10 seconds. The speed of the train is:  Choose the correct choice from the following answers:
A) 24 km/hr  B) 36 km/hr  C) 40 km/hr  D) 45 km/hr  E) None of these
Explanation:   Let the length of train be L m.   L/10 = (L+50)/14   14L= 10L+500   L= 125 m .   Speed = (25/2) m/s = (25/2) x 18/5= 45 Km/hr   Answer 45 km/hr
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A train passes a 50 metres long platform in 14 seconds and a man standing on the platform in 10 seconds. The speed of the train is: