Chapter 12 - Data Analysis and Probability - 12-6 Permutations and Combinations - Practice and Problem-Solving Exercises - Page 754: 16

504

Use the formula of permutation: $_{n}$P$_{r}$=$\frac{n!}{(n-r)!}$. Plug in 9 for N and 3 for R: $_{n}$P$_{r}$=$\frac{n!}{(n-r)!}$ $_{9}$P$_{3}$=$\frac{9!}{(9-3)!}$ -simplify- $_{9}$P$_{3}$=$\frac{9!}{6!}$ -write using factorial- $_{9}$P$_{3}$=$\frac{9*8*7*6*5*4*3*2*1}{6*5*4*3*2*1}$ -simplify- $_{9}$P$_{3}$=504