Discussion of Question with ID = 027 under Problems-on-Trains

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Question

A train running at a speed of 8m/s crosses a pole in 7sec. How long will it take to cross a platform of length 112m?

A

21 sec.

B

22 sec.

C

20 sec.

D

23 sec.

Soln.
Ans: a

The length of the train can be obtained from the time it takes to cross the pole. The length of the train = $8 × 7$ = 56m. To cross the platform it must travel a total distance equal to the combined lengths of the train and the platform at this speed. So time = ${56 + 112}/8$ = 21 seconds.


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