Question

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

• A. 1 : 3
• B. 3 : 2
• C. 3 : 4
• D. None of these

Answer 1

Answer: (B)

3 : 2

Let the speeds of the two trains be x m/sec and y m/sec .
Then, length of the first train = 27x metres
and length of the second train = 17y metres.
$\therefore \frac{27x+17y}{x+y}=23$
$27x+17y=23x+23y$
$4x=6y$
$\frac{x}{y}=\frac{3}{2}$
Hence The ratio of their speeds is 3:2