Task: Question Answering
Input (English): Problem: two men and 7 children complete a certain piece of work in 4 days while 4 men and 4 children complete the same work in only 3 days . the number of days required by 1 man to complete the work is 
Options: a ) 60 days , b ) 15 days , c ) 6 days , d ) 51 days , e ) 50 days
Output (English): b