How to calculate permutations on TI-84 calculator?

Calculating permutations on a TI-84 calculator can be done using the built-in nPr (Permutation) function. Here's how you do it:

1. Access the Math Menu: Press the MATH button to access the Math menu.

2. Select the Permutation Function: Use the arrow keys to navigate to the PROB column, and select 2:nPr and press ENTER. This will open the permutation function.

3. Enter the Values:

   • Enter the total number of items $n$.
   • Enter the number of items to arrange $r$.

4. Perform the Calculation: After entering $n$ and $r$, press ENTER again to calculate the number of permutations.

The calculator will display the result, which is the number of ways to arrange $r$ items from a set of $n$ items where the order of selection matters.

Here's an example: If you want to calculate the number of permutations for arranging 3 items from a set of 5, you would:

• Press MATH to access the Math menu.
• Choose PROB, select 2:nPr and press ENTER.
• Enter 5 for $n$ and 3 for $r$.
• Press ENTER to get the result.

The TI-84 calculator will then display the number of permutations, which in this case is calculated using the formula $P(n, r) = \frac{n!}{(n-r)!}$

, and for our example, it would be $\frac{5!}{(5-3)!} = 60$.

Remember that the permutation formula is $\frac{n!}{(n-r)!}$, where $!$ denotes factorial, and $r$ is typically less than or equal to $n$. The calculator performs this calculation for you when you use the nPr function.