Two trains X and Y are travelling in the same direction at 100 km/h and 60 km/h respectively. Train X crosses a man in train Y in 9 seconds. What is the length of train X?

  1. A. 80 m
  2. B. 100 m
  3. C. 120 m
  4. D. 150 m

Correct Answer: B. 100 m

Explanation

Relative speed = 100 - 60 = 40 km/h = 40 \times \frac{5}{18} = \frac{100}{9} m/s. The length of train X equals the relative distance covered, which is \frac{100}{9} \times 9 = 100 m.

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