Question

11. Find the number of unique permutations of the letters in the word CARDINALS w

Answer 1

Given the word:

CARDINALS

The word has 9 letters.

To find the unique permutations of the letters, we have:

First check for the letters that appears more than once.

Letter A appeared twice

Therefore, the permutation is:

$_nP_r=\frac{n!}{(n-r)!}=\frac{9!}{(9-2)!}=\frac{9!}{7!}$

$\begin{gathered} =\frac{9\ast8\ast7!}{7!}\text{ } \\ \\ \text{ = 9}\ast8\text{ = }72 \end{gathered}$

ANSWER:

72