A group consists of seven men and five women. Three people are selected to attend a conference.
a. In how many ways can three people be selected from this group of twelve?
b. In how many ways can three women be selected from the five women?
c. Find the probability that the selected group will consist of all women.
a. The number of ways to select three people from the group of twelve is 220
b. The number of ways to select three women from the group of five women is 0