Task: Question Answering
Input (English): Problem: a can do a piece of work in 3 days of 5 hours each and b alone can do it in 5 days of 3 hours each . how long will they take it to do working together 3 / 4 hours a day ? 
Options: a ) 6 days , b ) 5 days , c ) 10 days , d ) 9 days , e ) 8 days
Output (English): c