Task: Question Answering
Input (English): Problem: if 12 men or 20 women can do a piece of work in 54 days , then in how many days can 9 men and 21 women together do the work ? 
Options: a ) 10 days , b ) 30 days , c ) 20 days , d ) 80 days , e ) 40 days
Output (English): b