2018/09/11 by Dibyajyoti Deb, Deb, Dibyajyoti
Engineering · #Combinatorics (math.CO) #FOS: Mathematics #Vehicle License Plate Recognition
paper · pdf · doi:10.48550/arxiv.1809.04072
openalex publication_date 2018/09/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The 21 card trick is well known. It was recently shown in an episode of the popular YouTube channel Numberphile. In that trick, the audience is asked to remember a card, and through a series of steps, the magician is able to find the card. In this article, we look into the mathematics behind the trick, and look at a complete generalization of the trick. We show that this trick can be performed with any number of cards.