Question
A 420 m long train crosses a platform twice its length
in 3 min. Find the speed of the train. Section 1Solution
Speed of train = (Length of train + Length of Platform)/Required time Length of train = 420 m Crossing time of platform = 3 × 60 = 180 sec Length of platform = 420 × 2 = 840 m Let the speed of train be x. Speed of train = (420 + 840)/180 ⇒  x = 7 m/s
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