7.A group has 9 women and 7 men.

d. Suppose 2 members of the group refuse to work together. How many subgroups of 5 can be chosen

8. In how many ways can 16 people be seated:

a. In a row, if 4 of the 16 do not want to sit next to one another

b. In a row, if 3 of the 16 must be seated next to one another

c. In a circle, if 3 of the 16 must be seated next to one another.

d. In a circle, if 4 of the 16 do not want to sit next to one another.