"An *étude* (a French word meaning *study*) is an instrumental musical composition, usually short, of considerable difficulty, and designed to provide practice material for perfecting a particular musical skill."—[Wikipedia](https://en.wikipedia.org/wiki/%C3%89tude)
{nb('Pickleball Tournament','Pickleball.ipynb','Scheduling a doubles tournament fairly and efficiently')}
{nb('Project Euler Utilities','Project%20Euler%20Utils.ipynb','My utility functions for the Project Euler problems, including `Primes` and `Factors`')}
{nb('Properly Ordered Card Hands','Orderable%20Cards.ipynb','Can you get your hand of cards into a nice order with just one move?')}
{nb('Tracking Trump: Electoral Votes','Electoral%20Votes.ipynb','How many electoral votes would Trump get if he wins the state where he has positive net approval?')}
{nb('Weighing Twelve Balls','TwelveBalls.ipynb','A puzzle where you are given some billiard balls and a balance scale, and asked to find the one ball that is heavier or lighter, in a limited number of weighings')}
{nb('WWW: Who Will Win (NBA Title)?','WWW.ipynb','Computing the probability of winning the NBA title, for my home town Warriors, or any other team')}
|Run|LogicandNumberPuzzles|
|--|---|
{nb('Boggle / Inverse Boggle','Boggle.ipynb','Find all the words on a Boggle board; then find a board with a lot of words')}
{nb('Chemical Element Spelling','ElementSpelling.ipynb','Spelling words using the chemical element symbols, like CoIn')}
{nb('Cryptarithmetic','Cryptarithmetic.ipynb','Substitute digits for letters and make NUM + BER = PLAY')}
{nb('Four 4s, Five 5s, and Countdown to 2016','Countdown.ipynb','Solving the equation 10 _ 9 _ 8 _ 7 _ 6 _ 5 _ 4 _ 3 _ 2 _ 1 = 2016. From an Alex Bellos puzzle')}
{nb('Gesture Typing','Gesture%20Typing.ipynb','What word has the longest path on a gesture-typing smartphone keyboard?')}
{nb('Ghost','Ghost.ipynb','The word game Ghost (add letters, try to avoid making a word)')}
{nb('How Many Soldiers Do You Need to Beat the Night King?','NightKing.ipynb','Investigasting a battle between the army of the dead and the army of the living')}
{nb("Let's Code About Bike Locks",'Fred%20Buns.ipynb','A tale of a bicycle combination lock that uses letters instead of digits. Inspired by Bike Snob NYC')}
{nb('Pairing Socks','Socks.ipynb','What is the probability that you will be able to pair up socks as you randomly pull them out of the dryer?')}
{nb('Portmantout Words','Portmantout.ipynb','Find a long word that squishes together a bunch of words')}
{nb('The Puzzle of the Misanthropic Neighbors','Mean%20Misanthrope%20Density.ipynb','How crowded will this neighborhood be, if nobody wants to live next door to anyone else?')}
{nb('Sicherman Dice','Sicherman%20Dice.ipynb','Find a pair of dice that is like a regular pair of dice, only different')}
{nb("Sol Golomb's Rectangle Puzzle",'Golomb-Puzzle.ipynb','A Puzzle involving placing rectangles of different sizes inside a square')}
{nb('Spelling Bee','SpellingBee.ipynb','Find the highest-scoring board for the NY Times Spelling Bee puzzle')}
{nb('Translating English Sentences into Propositional Logic Statements','PropositionalLogic.ipynb','Automatically convert informal English sentences into formal Propositional Logic')}
{nb('How to Do Things with Words: NLP in Python','How%20to%20Do%20Things%20with%20Words.ipynb','Spelling Correction, Secret Codes, Word Segmentation, and more')}
{nb('When Cheryl Met Eve: A Birthday Story','Cheryl-and-Eve.ipynb',"Inventing new puzzles in the Style of Cheryl's Birthday")}
{nb("When is Cheryl's Birthday?",'Cheryl.ipynb',"Solving the *Cheryl's Birthday* logic puzzle")}
{nb("World's Longest Palindrome",'pal3.ipynb','Searching for a long Panama-style palindrome, this time letter-by-letter')}
{nb('xkcd 1313: Regex Golf (Part 2: Infinite Problems)','xkcd1313-part2.ipynb','Regex Golf: better, faster, funner. With Stefan Pochmann')}
{nb('xkcd 1313: Regex Golf','xkcd1313.ipynb','Find the smallest regular expression; inspired by Randall Monroe')}
{nb('xkcd 1970: Name Dominoes','xkcd-Name-Dominoes.ipynb','Lay out dominoes legally; the dominoes have people names, not numbers')}
{nb('A Concrete Introduction to Probability','Probability.ipynb','Code and examples of the basic principles of Probability Theory')}
{nb('Probability, Paradox, and the Reasonable Person Principle','ProbabilityParadox.ipynb','Some classic paradoxes in Probability Theory, and how to think about disagreements')}
{nb('Estimating Probabilities with Simulations','ProbabilitySimulation.ipynb','When the sample space is too complex, simulations can estimate probabilities')}
{nb('Economics Simulation','Economics.ipynb','A simulation of a simple economic game')}
{nb("Euler's Sum of Powers Conjecture","Euler's%20Conjecture.ipynb",'Solving a 200-year-old puzzle by finding integers that satisfy a<sup>5</sup> + b<sup>5</sup> + c<sup>5</sup> + d<sup>5</sup> = e<sup>5</sup>')}
{nb('How to Count Things','How%20To%20Count%20Things.ipynb','Combinatorial math: how to count how many things there are, when there are a lot of them')}
{nb('Symbolic Algebra, Simplification, and Differentiation','Differentiation.ipynb','A computer algebra system that manipulates expressions, including symbolic differentiation')}
