Permutations

Ordered arrangements of $k$ objects chosen without replacement from $n$ possible objects. Used when counting, when order matters. Box Occupant Based Thinking helps to visualize permutations

Notation

${}_n$P${}_r$

n = # of occupants r = # of boxes

P(n,r)

Permutation formula

${}_n{P}_r=\frac{n!}{(n-r)!}$

Concepts

• Permutations with Repetition
• Permutations with Identical Items
• Pascal Routes