Task: Question Answering
Input (English): Problem: working together at their respective constant rates , machine a and machine b can produce 1600 units in 8 hours . working alone , machine b would complete that same output in 50 % more time . if machine a were to work on its own for an 8 - hour shift , what percent of the 1600 unit total would it produce ? 
Options: a ) 25 , b ) 33 , c ) 50 , d ) 67 , e ) 75
Output (English): b