Two committees, one with six and one with seven people, are to be selected from a group of eighteen people, with no one person serving on both committees at the same time. In how many ways can this be done?
number of ways to choose first committee
= C(18,6) = 18564
that leaves 12 people and we choose 7 of those
= C(12,7) = 792
number of ways = 18564*792 = 14,702,688