Question

sally has 4 red flags, 5 green flags, and 6 white flags. How many 15 flag signals can she run up a flag pole?

Answer 1

The number of 15 flag signals that can be run up is:
\[\frac{15!}{4!5!6!}\]

Answer 2

The result comes from the permutations theorem:
If n given things can be divided into c classes such that things belonging to the same class are alike while things belonging to different classes are different , then the number of permutations of these things taken all at a time is\[\frac{n!}{n _{1}!n _{2}!.....n _{c}!}\]