Now lets make the problem complex, Lets include memory and allow guessing instead of strict order. To clarify, you are attempting to guess which card is next, by remembering cards that we have already turned over, we can improve our chances of a correct guess and as we get down to fewer cards, our chances of a correct guess increases. The next to last card, we have a 50% chance of guessing right (with perfect memory) and 100% chance on last card. This is a more intriguing problem (Somewhat applicable to blackjack). Now what would the expected number of cards be? I have not worked it out but interested in seeing concept of others.