Question 872052
Of 16 possible books you plan to take 8 with you on vacation, how many different collections of 8 can you bring?
<pre>
If you have the 8 books in a stack, it does not matter what order
they are stacked in, so this is a COMBINATION problem, not a PERMUTATION
problem.

The is the combination of 16 things taken 8 at a time.

C(16,8) = 12870

On the TI-83 or 84

Press ON
Press CLEAR
Press 16
Press MATH
Press 3
Press 8
Press ENTER

You will see

16 nCr 8
            12870

Edwin</pre>