Task: Question Answering
Input (English): Problem: working together , printer a and printer b would finish the task in 40 minutes . printer a alone would finish the task in 60 minutes . how many pages does the task contain if printer b prints 4 pages a minute more than printer a ? 
Options: a ) 250 , b ) 375 , c ) 450 , d ) 480 , e ) 500
Output (English): d