The task is to generate the correct answer for a given math problem.

[Q]: Problem: two trains running in opposite directions cross a man standing on the platform in 37 seconds and 27 seconds respectively and they cross each other in 29 seconds . the ratio of their speeds is :
[A]: 1 : 


[Q]: Problem: 12 men work 8 hours per day to complete the work in 10 days . to complete the same work in 8 days , working 15 hours a day , the number of men required ?
[A]: 8 days


[Q]: Problem: a man buys an article for $ 100 . and sells it for $ 130 . find the gain percent ?
[A]:
30