## Algebra 1: Common Core (15th Edition)

We know that: $_nC_r =\frac{_nP_r}{r!} = \frac{n!}{(n-r)!r!}$ $_3C_0 = \frac{3!}{(3-0)!0!}$ $\frac{ 3!}{3!}$ Which we know is equal to $\underline 1$.