Task: Question Answering
Input (English): Problem: two trains of equal lengths take 9 sec and 15 sec respectively to cross a telegraph post . if the length of each train be 120 m , in what time will they cross other travelling in opposite direction ? 
Options: a ) 10 , b ) 11.3 , c ) 13 , d ) 14 , e ) 15
Output (English): b