Multiple choice

A train, running at a speed of 46 kmph, takes 21 seconds to pass a platform. Also, it takes 12 seconds to pass a man walking at a speed of 10 kmph in the same direction as the train. Find the length of the platform.

  1. 130.33 m

  2. 160.50 m

  3. 148.33 m

  4. 180.45 m

  5. 100.50 m
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Train speed = 46 kmph = 12.77 m/s. Man speed = 10 kmph = 2.77 m/s. Relative speed = 10 m/s. Train length = 10 m/s * 12 s = 120 m. Total distance for platform = 12.77 m/s * 21 s = 268.27 m. Platform length = 268.27 - 120 = 148.27 m, which rounds to 148.33 m.

AI explanation

First convert the relative speed of the train and the man from kmph to m/s: (46 - 10) multiplied by 5/18 equals 10 m/s. Since the train takes 12 seconds to pass the man, its length is 10 multiplied by 12, which equals 120 m. Next, convert the train's speed to m/s: 46 multiplied by 5/18 equals 115/9 m/s. The total distance to cross the platform is (120 + platform length), so (120 + platform length) equals 115/9 multiplied by 21, which simplifies to 268.33. Therefore, the platform length is 268.33 - 120, which is 148.33 m.

Keep practicing — related questions