Task: Question Answering
Input (English): Problem: a and b complete a work in 6 days . a alone can do it in 10 days . if both together can do the work in how many days ? 
Options: a ) 3.75 days , b ) 3.78 days , c ) 3.25 days , d ) 3.15 days , e ) 2.75 days
Output (English): a