Question
Length of a train is double the length of a platform.
If the train crosses the platform in 72 seconds, then find the time taken by train to cross a pole.Solution
Let the speed of train be 'v' m/s and the length of platform be 'L' metres.
Length of train = '2L' metres
So, (L + 2L) = '72v'
Or, 3L = 72v
So, 'L' = 24v ---------- (I)
Required time = (2L/v)
= (48v/v) [from equation (I) ]
= 48 seconds
Hence, option c.
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