Combinatorics Flashcards
1
Q
Permutation
A
n!/(n-r)!
2
Q
Repetition allowed, order matters
A
N^n
3
Q
Repetition allowed, order does not matter
A
(N+n-1)!/n!(N-1)!
4
Q
Repetition not allowed, order does matter
A
N/(N-n)!
5
Q
Repetition not allowed, order does not matter
A
N!/n!(N-n)!
