Task: Question Answering
Input (English): Problem: p can do a work in the same time in which q and r together can do it . if p and q work together , the work can be completed in 10 days . r alone needs 50 days to complete the same work . then q alone can do it in 
Options: a ) 30 days , b ) 25 days , c ) 20 days , d ) 15 days , e ) 24 days
Output (English): b