Task: Question Answering
Input (English): Problem: p alone can complete a job in 12 days . the work done by q alone in one day is equal to one - half of the work done by p alone in one day . in how many days can the work be completed if p and q work together ? 
Options: a ) 5 , b ) 6 , c ) 7 , d ) 8 , e ) 9
Output (English): d