21 Card Trick

The original 21 Card Trick !

The player is asked to memorise one card from 21 random cards displayed in 3 columns. The game shuffles the cards and re-displays them in 3 columns. The player is asked to indicate which column the memorised card is in but the actual card is not disclosed. This is repeated 3 times and the final time the game discloses the card the player has memorised.