Probability help please!!!

Seven men and five women have been nominated to serve on a committee. The committee consists of four members who are to be chosen from the seven men and five women.
a) In how many different ways can the committee be chosen?
b) In how many of these ways will the committee consist of two men and two women?
c) Assuming that each choice of four members is equally likely, find the probability that the committee will contain exactly two men.



thanks in advance!

let nCr denote n! / (r! (n-r)!)

a) 12C4
b) 7C2 * 5C2
c) 7C2 * 5C2 / 12C4