### Instruction: My club has 25 members.  In how many ways can I choose members to form a 4-person executive committee?### Response: I need to count how many different combinations of 4 people I can select from 25 people.
I don't care about the order of the committee members, just who is on it.
This means I can use the formula for combinations, which is nCr = n! / (r! (n-r)!), where n is the total number of items and r is the number of items to choose.
In this case, n = 25 and r = 4.
Plugging these values into the formula, I get 25C4 = 25! / (4! 21!) = (25 x 24 x 23 x 22) / (4 x 3 x 2 x 1) = 12,650.