Task: Question Answering
Input (English): Problem: two trains of equal lengths take 10 sec and 15 sec , respectively , to cross a telegraph post . if the length of each train is 120 m , in what time will they cross each other , travelling in opposite directions ? 
Options: a ) 17 sec , b ) 12 sec , c ) 18 sec , d ) 19 sec , e ) 52 sec
Output (English): b