# Posts Tagged ‘ mathematical puzzle ’

## R midterms

November 9, 2012
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Here are my R midterm exams, version A and version B in English (as students are sitting next to one another in the computer rooms), on simulation methods for my undergrad exploratory statistics course. Nothing particularly exciting or innovative! Dedicated ‘Og‘s readers may spot a few Le Monde puzzles in the lot… Two rather entertaining

## the large half now

October 28, 2012
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The little half puzzle proposed a “dumb’ solution in that players play a minimax strategy. There are 34 starting values less than 100 guaranteeing a sure win to dumb players. If instead the players maximise their choice at each step, the R code looks like this: and there are now 66 (=100-34, indeed!) starting values

## the little half (another Le Monde puzzle)

October 27, 2012
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I found this Le Monde puzzle of June 16 I had stored and then somehow forgotten with my trips to Japan and Australia: There are n beans in a box, with 98≤n≤102). Two players take at each round either one bean from the box or “the little half” (i.e. the integral part of the half)

## Le Monde puzzle (rainy Sunday!)

October 20, 2012
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On October 14, the weekend edition of Le Monde had the following puzzle: consider four boxes that contain all integers between 1 and 9999, in such a way that for any N, N, 2N, 3N, and 4N are in four different boxes. If 1,2,3 and 4 are in boxes labelled 1,2,3 and 4, respectively, in

## Le Monde puzzle [#783]

July 20, 2012
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$Le Monde puzzle [#783]$

In a political party, there are as many cells as there are members and each member belongs to at least one cell. Each cell has five members and an arbitrary pair of cells only shares one member. How many members are there in this political party? Back to the mathematical puzzles of Le Monde (science

## \verbatim [beamer package]

June 11, 2012
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Once again working on my slides for the AMSI Lecture 2012 tour, it took me a while to get the following LaTeX code (about the family reunion puzzle) to work: \begin{frame} \slidetitle{A family meeting} \begin{block}{Random switch of couples} \only<1>{ \begin{itemize} \item Pick two couples at random with probabilities proportional to the

## Le Monde puzzle [#755?]

January 27, 2012
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Le Monde puzzle of last weekend was about sudoku-like matrices. Consider an (n,n) matrix containing the integers from 1 to n². The matrix is “friendly” if the set of the sums of the rows is equal to the set of the sum of the columns. Find examples for n=4,5,6. Why is there no friendly matrix

## Le Monde puzzle [#754]

December 25, 2011
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The pre-X’mas puzzle in Le Monde weekend edition is about “magical numbers” having as digits all digits between 0 and n (at least once) and being multiple of all digits between 1 and (n+1). Easy, isn’t it?! I thought so while driving down to the Alps on Saturday and (on Monday early morning) I tried

## Le Monde puzzle [#752]

December 8, 2011
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After a loooong break, here is one Le Monde mathematical puzzle I had time to look at, prior to going to Dauphine for a Saturday morning class (in replacement of my R class this week)! The question is as follows: A set of numbers {1,…,N} is such that multiples of 4 are tagged C and