Tag Archives: Test your intuition

Test Your Intuition (17): What does it Take to Win Tic-Tac-Toe

(A few more quantum posts are coming. But let’s have a quick break for games.) Tic Tac Toe is played since anciant times. For the common version, where the two players X and O take turns in marking the empty squares … Continue reading

Posted in Games, Test your intuition | Tagged , , | 40 Comments

Discrepancy, The Beck-Fiala Theorem, and the Answer to “Test Your Intuition (14)”

The Question Suppose that you want to send a message so that it will reach all vertices of the discrete -dimensional cube. At each time unit (or round) you can send the message to one vertex. When a vertex gets the … Continue reading

Posted in Combinatorics, Test your intuition | Tagged , | 6 Comments

Test Your Intuition (14): A Discrete Transmission Problem

Recall that the -dimensional discrete cube is the set of all binary vectors ( vectors) of length n. We say that two binary vectors are adjacent if they differ in precisely one coordinate. (In other words, their Hamming distance is 1.) This … Continue reading

Posted in Combinatorics, Test your intuition | Tagged , | 35 Comments

Test Your Intuition (13): How to Play a Biased “Matching Pennies” Game

Recall the game “matching pennies“. Player I has to chose between ’0′ or ’1′, player II has to chose between ’0′ and ’1′.No player knows what is the choice of the other player before making his choice. Player II pays … Continue reading

Posted in Games, Test your intuition | Tagged | 5 Comments

False Beliefs in Mathematics

Test your intuition: For two n by n matrices A and B, is it always the case that tr(ABAB) = tr(ABBA)?

Posted in Mathematics over the Internet, Test your intuition | Tagged , | 6 Comments

Test Your Intuition (12): Perturbing a Polytope

Let P be a d-dimensional convex polytope. Can we always perturb the vertices of P moving them to points with rational coordinates without changing the combinatorial structure of P? In order words, you require that a set of vertices whose … Continue reading

Posted in Convex polytopes, Test your intuition | Tagged , | 4 Comments

Test Your Intuition (11): Is it Rational to Insure a Toaster

Here is a question from last year’s exam in the course “Basic Ideas of Mathematics”:   You buy a toaster for 200 NIS ($50) and you are offered one year of insurance for 24 NIS ($6).   a) Is it … Continue reading

Posted in Probability, Rationality, Teaching, Test your intuition | Tagged , | 18 Comments

Test Your Intuition (10): How Does “Random Noise” Look

This is a bit unusual post in the “test your intuition” corner as the problem is not entirely formal.   How does random noise in the digital world typically look? Suppose you have a memory of n bits, or a memory based on a larger … Continue reading

Posted in Probability, Test your intuition | Tagged , | 3 Comments

Answer to Test Your Intuition (9)

Two experimental results of 10/100 and 15/100 are not equivalent to one experiment with outcomes 3/200. (Here is a link to the original post.) One way to see it is to think about 100 experiments. The outcomes under the null … Continue reading

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

Buffon’s Needle and the Perimeter of Planar Sets of Constant Width

Here is an answer to “Test your intuition (8)”. (Essentially the answer posed by David Eppstein.) (From Wolfram Mathworld) Buffon’s needle problem asks to find the probability that a needle of length will land on a line, given a floor … Continue reading

Posted in Convexity, Probability, Test your intuition | Tagged | 5 Comments