Ace of spades Use Definition 4.32 to compute the probability that you draw an ace of spades conditional on having drawn an ace when you draw one card from a well-shuffled deck. You can imagine a game show host who draws a card at random and announces that the card is an ace, and a con testant who has to guess what kind of ace it is. Given what you know about that card, what is the probability that it is the ace of spades?