Ben Chuanlong Du's Blog

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Probability to Get a Complete Deck of Cards?

Suppose a poker games requires 4 decks of poker. After the game, the cards are put back into the 4 decks randomly. Now there is another game which requires only 1 deck of poker, so we want to open some decks of the poker and find a complete set of …

Chance to Take One's Own Seat?

There are \(N\) seats on a plane. Suppose the first passengers is drunk and he takes a seat randomly. For each of the other passengers, if his/her seat is not taken by other people, then he/she sits on his/her own seat, otherwise he/she takes a seat …

Expected Gain of Tossing a Dice

Suppose you toss a symmetric dice. You are allowed to quit the game and get money which equals the total points you get at any time if 6 has never showed up. Whenever 6 shows up, the game is over and you get nothing. For example, if the first three …