Question

Nishu is standing on a railway bridge which is 180 m long. He finds that a train crosses the bridge in 20 seconds but himself in 8 seconds. Find the speed of the train? 1) 35 kmph 4) 70 kmph 2) 54 kmph 3) 62 kmph 5) None of these
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Answer 1

Answer:

A man is standing on a railway bridge which is 180m long he finds that a train crosses the bridge in 20 seconds but himself in 8 seconds find the length of the train and its speed

Then, the train covers x metres in 8 seconds (train is actually covering itself because length of man is very less compartable to train)and (x + 180) metres in 20 seconds. ∴ x/8 =( x + 180) / 20 ⇔ 20x = 8(x + 180) ⇔ x = 120. ∴ Length of the train = 120 m.20-May-2015