Task: Question Answering
Input (English): Problem: a can do a piece of work in 15 days and b in 20 days . they began the work together but 5 days before the completion of the work , a leaves . the work was completed in ? 
Options: a ) 8 days , b ) 10 days , c ) 15 days , d ) 11 3 / 7 days , e ) none of these
Output (English): d