Question

The speed of train A is x km/ hr crosses 120 m platform in 16 seconds and the speed of train B is 108 km/hr it crosses the same platform in 40/3 seconds. If the length of the train A and B are the same, find the value of x.

• A. 80 kmph
• B. 90 kmph
• C. 70 kmph
• D. 60 kmph

Answer 1

Answer:

B. 90 kmph

Solution: Solution: Speed of the train = x kmph Length of the platform = 120m Time taken by the train to cross the platform = 16 seconds Length of the both trains = y m ( y + 120)/(x × (5/18)) = 16 (y + 120) = 5x/18 × 16 (y + 120) = 40x/9 x = (y + 120)× 9/40 Again, (y + 120) /(108 × 5/18) = 40/3 (y + 120)/30 = 40/3 (y + 120) = 400 y = 280m x = (280 + 120) × 9/40 = 90kmph Hence, option(2) is correct.