A group consists of five men and five women. Four people are selected to attend a conference,
a. In how many ways can four people be selected from this group of ten?
b. In how many ways can four 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 four people from the group of ten is
b. The number of ways to select four women from the group of five women is 0.
c. The probability is
(Type an integer or a simplified fraction.)