Task: Question Answering
Input (English): Problem: if a , b and c together can finish a piece of work in 2 days . a alone in 12 days and b in 18 days , then c alone can do it in ? 
Options: a ) 5 days , b ) 4 days , c ) 3 days , d ) 2 days , e ) 7 days
Output (English): c