Another bonus question - testing the means?

Hi all,

here is another of the bonus questions we had to choose from. I think I want to compare the difference between means (Ho = 24, Ha not = 24), but I am not sure what to do and the second half of the question has really been bothering me. I am realy interested in how to solve this. Thanks

The question:

72 students enroll in different sections of a course. Test the hypothesis that people do not care what professor is teaching when they choose a course. Test the hypothesis that Prof. c is preferred by 20% of all students and that the rest are evenly split between Porfs A and B. Which fits better, doe either fit well at all?

Prof A - 25 students

Prof B - 28 students

Prof C - 19 Students