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 ? Options.
A) 1 : 1	B) 2 : 1	C) 2 : 3	D) 3 : 2	E) 1 : 2
Let the speeds of the two trains be x m/sec and y m/sec respectively.   Then, length of the first train = 27 x meters, and   length of the second train = 17 y meters.   (27 x + 17 y) / (x + y) = 23   =&gt; 27 x + 17 y = 23 x + 23 y   =&gt; 4 x = 6 y   =&gt; x/y = 3/2.   Answer : 3 : 2
<result>D</result>
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 ?