A train 200 metres long is moving at the rate of 40 kmph. In how many seconds will it cross a man standing near the railway line?

Correct Option: 18

To find the time taken by the train to cross a standing man, we must use the formula: Time = Distance / Speed. When a train crosses a standing man, the distance to be covered is equal to the length of the train itself, which is given as 200 metres. First, we convert the speed of the train from kilometres per hour (kmph) to metres per second (m/s). Speed = 40 kmph = 40 × (5 / 18) m/s = 200 / 18 m/s = 100 / 9 m/s. Now, using the formula for time: Time = 200 / (100 / 9) = 200 × 9 / 100 = 2 × 9 = 18 seconds. Thus, the train will cross the man standing near the railway line in exactly 18 seconds. Other options are incorrect as they do not match this calculation. Therefore, Option D is the correct answer.