We have a normal deck of 52 cards. We want to do the following magic trick:

A person from the audience chooses 5 random cards. The magician's assistant looks at the 5 cards, chooses 4 of them, hands them to the magician one by one face up and keeps the other one hidden. The magician then guesses the fifth card (the one that the assistant kept hidden) just by looking at the 4 cards he was handed in.

Is it possible to devise a strategy, so that no matter what the original 5 cards were, the trick always works?

the first card is used to establish suit ebing that at least two of the cards have the same suit. after that the assistant hand the next card over either using two fingers opposite the thumb or one. One indicates the value of the card is A-7, two indicates 8-K. this process is repeated with the next card again roughly splitting the remaining 6 or 7 cards. the last card might be difficult in that the assistant may have to use all four fingers opposite thumb if the card is the seven.

Posted by Steve on 2003-05-08 20:22:05