1) A computer distributor's stock consists of 10 Windows and 12 Mac computers. He wants to send 11 computers to one of his outlet stores. If the computers are selected at random so that all groups of 11 are equally likely, what is the probability that the 11 computers he sends (from the possible 22 computers) will consist of 4 Windows computers and 7 Mac computers?

2) A department store window designer has 20 new outfits available to dress 5 mannequins for a window display. How many different ways can he dress the mannequins?

3)The local community Chess Club needs to select three members for a new Board of Officers. The club has 20 members who are eligible to serve as officers. The Board of Officers consists of the President, the Vice President, and the Executive Secretary. How many possible ways can the club select the 3 positions from the 20 eligible members?