Arrangements (VCE SSCE Mathematical Methods): Flashcards

Ordering of objects where sequence matters

Permutations

Order matters

$n!$

$n \times (n-1) \times (n-2) \times \cdots \times 2 \times 1$

$\frac{n!}{(n-r)!}$

$^nP_r$

$1$

Deal with the restriction first

$n^r$