Multiple choice

Directions: Answer the questions independently of each other. Two trains A and B of equal lengths i.e. 224meters are moving towards each other at a speed of 51 kmph and 57 kmph while a man is moving towards train A at a speed of 6.6kmph. What is the difference of time taken(in sec) by these two trains to cross the man.

  1. 5 sec

  2. 1 sec

  3. 2 sec

  4. 6 sec
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Relative speed of Train A and man = 51 + 6.6 = 57.6 kmph = 16 m/s. Time A = 224/16 = 14s. Relative speed of Train B and man = 57 - 6.6 = 50.4 kmph = 14 m/s. Time B = 224/14 = 16s. Difference = 16 - 14 = 2s.

AI explanation

The man is moving towards train A, so their relative speed is the sum of their speeds: 51 kmph plus 6.6 kmph, which equals 57.6 kmph. Converting this to meters per second requires multiplying by 5/18, giving a relative speed of 16 m/s. The time taken by train A to cross the man is its length divided by this relative speed: 224 divided by 16, which is 14 seconds. The man is moving in the opposite direction of train B, so their relative speed is 57 kmph minus 6.6 kmph, resulting in 50.4 kmph, which converts to 14 m/s. The time taken by train B to cross the man is 224 divided by 14, which equals 16 seconds. The difference between these times is 16 minus 14, resulting in 2 seconds.

Keep practicing — related questions