Two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and they cross each other in 23 seconds. The ratio of their speeds is:

Aptitude Problems on Trains Difficulty: Medium
Choose an option
  • A
    3:2
  • B
    4:3
  • C
    5:4
  • D
    7:5

Answer

Correct Answer: 3:2

Explanation

Given

  • Train 1 passes a man in 27 s
  • Train 2 passes a man in 17 s
  • They cross each other in 23 s (opposite)

Let speeds be v1, v2 (m/s)Lengths: l1 = v1 × 27, l2 = v2 × 17Crossing: (l1 + l2)/(v1 + v2) = 23⇒ 27v1 + 17v2 = 23v1 + 23v2⇒ 4v1 = 6v2 ⇒ v1/v2 = 3:2

Discussion & Comments
No comments yet. Be the first to comment!
Join Discussion