How to calculate combinations on TI-84 calculator?

Calculating combinations on a TI-84 calculator is straightforward using the built-in combination function. Here's how you do it:

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

Select the Prob Function: choose PROB and then select 3:nCr and press ENTER. This will open the combination function.

Enter the Values:

Enter the total number of items $n$. Enter the number of items to choose $k$. Perform the Calculation: After entering $n$ and $k$, press ENTER again to calculate the number of combinations.

The calculator will display the result, which is the number of ways to choose $k$ items from a set of $n$ items without regard to the order of selection.

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

Press MATH to access the Math menu. choose PROB, select 3:nCr, and press ENTER. Enter 5 for $n$ and 3 for $k$. Press ENTER to get the result. The TI-84 calculator will then display the number of combinations, which in this case is 10.

Remember that the combination formula is $\frac{n!}{k! * (n-k)!}$, where $!$ denotes factorial. The calculator performs this calculation for you when you use the comb function.