
# 5.3: Summary


• The number of ways of choosing $$r$$ objects from $$n$$ types of objects (with replacement or repetition allowed) is $$(\binom{n}{r}) = \binom{n+r−1}{r}$$.
• The number of ways of arranging $$n$$ objects where $$r_i$$ of them are of type $$i$$ (indistinguishable), is $$\binom{n}{r_1,r_2,...,r_m}$$.
• Notation:
• $$(\binom{n}{r})$$
• $$\binom{n}{r_1,r_2,...,r_m}$$

This page titled 5.3: Summary is shared under a CC BY-NC-SA license and was authored, remixed, and/or curated by Joy Morris.