Lecture 19: Recitation - A combinatorial card trick

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Taught by ArsDigita
  • Currently 4.0/5 Stars.
4028 views | 1 rating
Lesson Summary:

In this lesson, we explore a combinatorial card trick and analyze the strategy used to perform it. We learn how to determine the deck size necessary for the strategy to work and how many possible strategies exist for a given deck size and number of cards chosen. We also discover that some strategies are bad and won't work for certain deck sizes and card choices. The lesson is a fascinating dive into the world of combinatorics and probability, showcasing the intricacies and challenges of creating and analyzing mathematical tricks.

Lesson Description:

Learn about and analyze a combinatorial card trick.

More information about this course:
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Additional Resources:
Questions answered by this video:
  • What is an example of a combinatorial card trick?
  • Given a deck of size d <= upper bound, is there a strategy that works for this card trick?
  • How many possible strategies are there for this trick?
  • If there are 7 cards in a deck, and we choose 3 cards, how many suits can you have and still guarantee that you have 2 cards in the same suit?
  • If n = 3, how big of a deck will not admit a strategy for this card trick?
  • If you have a set of three letters, how can you encode them using reverse alphabetical order?
  • Staff Review

    • Currently 4.0/5 Stars.
    This recitation is focused nearly entirely on a card magic trick and the math behind it. Make sure to check out the problem set that goes along with this video. There is a lot of math that was used in this course that is behind this problem, which makes it pretty interesting, although the math is rather dry and complicated and some points. These ideas lead into cryptography in the next and final lecture.