Task: Question Answering
Input (English): Problem: a and b can do a work in 8 days , b and c can do the same work in 12 days . a , b and c together can finish it in 6 days . a and c together will do it in how many days ? 
Options: a ) 7 , b ) 6 , c ) 5 , d ) 8 , e ) 9
Output (English): d