Determine how many cards, in an ordinary deck of fifty-two, fit the description:

Spades or 9's

There are 4 suites, and 13 cards of each kind. That means there are 4 9s and 13 Spades. Of those 13 Spades, 12 are not 9s and 1 is a 9, thus we are overcounting, so there are 4 + 13 - 1 Spades or 9s in the deck. 16