Task: Question Answering
Input (English): Problem: two trains of length 100 m and 200 m are running towards each other on parallel lines at 42 kmph and 30 kmph respectively . in what time will they be clear of each other from the moment they meet ? 
Options: a ) 18 sec , b ) 15 sec , c ) 21 sec , d ) 20 sec , e ) 19 sec
Output (English): b