Don't want the answer just the formula on how to figure this out. two trains are traveling on parallel tracks. Train A is going 40mph and crosses the station at 4:10, Train B is going 60mph and crosses the station at 4:25 when will train B catch up to train A? Could someone just get me started?

Answer 1

You will find almost the identical question here, only the numbers are different.

http://www.jiskha.com/display.cgi?id=1258865597