There are 19 nominees for 6 vacancies on a city
commission, 8 Republicans and 11 Democrats.
(a) How many ways can the vacancies be filled
by 2 Republicans and 4 Democrats?
(8 Republicans choose 2) times (11 Democrats choose 4) =
8C2×11C4 = 9240
(b) If nominees to fill the vacancies are chosen
at random, what is the probability of choosing
2 Republicans and 4 Democrats?
9240 ways out of (19 nominees choose 6)
9240÷(19C6) = 9240÷27132 =
which reduces by 84 to about 34% of the time.
Edwin