Chapter 12.7, Problem 53MR

To determine

To find: The number of permutations or combinations.

Answer to Problem 53MR

The solution is $9$ .

Explanation of Solution

Given:

The given term is,

  $C{}_1$

Calculation:

For any positive integers,

  $C{}_r=\frac{n!}{r!\left(n-r\right)!}$

The value is calculated as,

  $\begin{array}{c}C{}_1=\frac{9!}{1!\left(9-1\right)!}\\ =\frac{9\times 8!}{8!}\\ =9\end{array}$

Therefore, the solution is $9$ .