Task: Question Answering
Input (English): Problem: the amount of time that three people worked on a special project was in the ratio of 4 to 3 to 5 . if the project took 120 hours , how many more hours did the hardest working person work than the person who worked the least ? 
Options: a ) 25 hours , b ) 30 hours , c ) 20 hours , d ) 26 hours , e ) 32 hours
Output (English): c