Two trains running in opposite directions cross a man standing on the platform in 25 seconds and 18 seconds respectively and they cross each other in 20 seconds. The ratio of their speeds is: Answers: A) 3 : 1 B) 3 : 2 C) 3 : 8 D) 2 : 5 E) 3 : 4
Let the speeds of the two trains be x m/sec and y m/sec respectively. Then, length of the first train = 25 x meters, and length of the second train = 18 y meters. (25 x + 18 y) / (x + y) = 20 ==&gt;   25 x + 18 y = 20 x + 20 y ==&gt; 5 x = 2 y ==&gt; x/y = 2/5   Answer: Option 2 : 5
<result>D</result>
Two trains running in opposite directions cross a man standing on the platform in 25 seconds and 18 seconds respectively and they cross each other in 20 seconds. The ratio of their speeds is: