The pool of students in a calculus class consist of 22 sophomore and 8 freshmen. If seven students are to be selected at random from the class, (c) how many different groups of seven students consist...

The pool of students in a calculus class consist of 22 sophomore and 8 freshmen. If seven students are to be selected at random from the class,

(c) how many different groups of seven students consist entirely of sophomore?
(d) what is the probability that the group will consist entirely of freshmen? (Leave as a fraction)