If 9 cards are drawn at once from a deck, what is the probability that exactly 4 of the cards will be clubs?

The total number of possible sets that can be made from choosing 9 cards from 52 =

C(52,9)  = 3,679,075,400

But....the ones we are interested in have us choosing any 4 clubs from 13, and from the other 39 cards, selecting any 5 of them.

So we have

C(13.4) * C(39,5)  = 411,666,255

So

411,666,255 / 3,679,075,400  = about 11.2%