Task: Question Answering
Input (English): Problem: a and b can do a piece of work in 2 days . with the help of c they finish the work in 1 days . c alone can do that piece of work in ? 
Options: a ) 1.5 days , b ) 4 days , c ) 3 days , d ) 1 day , e ) 2 days
Output (English): e