Tag Archives: Test your intuition

TYI 39 : Can a coalition of children guarantees all being in the same class?

Posted on July 25, 2019 by

There is a class of children that have just finished elementary school. Now they all move from elementary school to high school and classes are reshuffled. Each child lists three friends, and the assignment of children into classes ensures that … Continue reading →

Posted in Combinatorics, Economics, Mathematics to the rescue, Test your intuition | Tagged | 2 Comments

Test Your Intuition (or simply guess) 37: Arithmetic Progressions for Brownian Motion in Space

Posted on March 7, 2019 by

  Consider a Brownian motion in three dimensional space. What is the largest number of points on the path described by the motion which form an arithmetic progression? (Namely, , so that all are equal.)   A 2-D picture; In … Continue reading →

Posted in Probability, Test your intuition | Tagged , | 8 Comments

Test Your Intuition (or knowledge, or programming skills) 36

Posted on March 4, 2019 by

How much is   The product ranges over all primes. In other words, Just heard it from Avinoam Mann.  

Posted in Number theory, Test your intuition | Tagged | 12 Comments

Test Your Intuition 35: What is the Limiting Distance?

Posted on June 29, 2018 by

(Just heard it today from Sergiu Hart.) At time t=0, point A is at the origin (0,0) and point B is distance 1 appart at (0,1). A moves to the right (on the x-axis) with velocity 1  and B moves … Continue reading →

Posted in Test your intuition | Tagged , | 18 Comments

Test Your Intuition (34): Tiling high dimensional spaces with two-dimensional tiles.

Posted on April 15, 2018 by

A tile is a finite subset of . We can ask if can or cannot be partitioned into copies of . If   can be partitioned into copies of we say that tiles . Here is a simpe example. Let consists of … Continue reading →

Posted in Combinatorics, Test your intuition | Tagged | 7 Comments

Stan Wagon, TYI 32: Ladies and Gentlemen: The Answer

Posted on October 22, 2017 by

TYI 32, kindly offered by Stan Wagon asked A round cake has icing on the top but not the bottom. Cut out a piece in the usual shape (a sector of a circle with vertex at the center), remove it, … Continue reading →

Posted in Combinatorics, Geometry, Test your intuition | Tagged , | 8 Comments

Ladies and Gentlemen, Stan Wagon: TYI 32 – A Cake Problem.

Posted on October 19, 2017 by

The following post was kindly contributed by Stan Wagon. Stan (Wikipedea) is famous for his books, papers, snow-sculptures, and square-wheels bicycles (see picture below) !     A round cake has icing on the top but not the bottom. Cut out a … Continue reading →

Posted in Combinatorics, Guest blogger, Test your intuition | Tagged , , | 8 Comments

TYI 31 – Rados Radoicic’s Rope Problem

Posted on October 4, 2017 by

  Ropemaker (source) Rados Radoicic wrote me: “Several years back, I heard the following puzzle that turns out to be rather ‘classical’: “There are N ropes in a bag. In each step, two rope ends are picked uniformly at random, tied … Continue reading →

Posted in Combinatorics, Probability, Test your intuition | Tagged , | 7 Comments

TYI 30: Expected number of Dice throws

Posted on September 7, 2017 by

Test your intuition: You throw a dice until you get 6. What is the expected number of throws (including the throw giving 6) conditioned on the event that all throws gave even numbers. follow-up post

Posted in Combinatorics, Probability, Test your intuition | Tagged | 38 Comments

Test your intuition 29: Diameter of various random trees

Posted on September 5, 2017 by

Both trees in general and random trees in particular are wonderful objects. And there is nothing more appropriate to celebrate Russ Lyons great birthday conference “Elegance in Probability” (taking place now in Tel Aviv) than to test your intuition, dear … Continue reading →

Posted in Combinatorics, Probability, Test your intuition | Tagged , | 19 Comments