Task: Question Answering
Input (English): Problem: two trains of length 100 m and 200 m are 100 m apart . they start moving towards each other on parallel tracks , at speeds 36 kmph and 72 kmph . in how much time will the trains cross each other ? 
Options: a ) 40 / 6 , b ) 40 / 3 , c ) 40 / 9 , d ) 40 / 2 , e ) 40 / 1
Output (English): b