MIT Mystery Hunt Puzzle Index: Category Index

Mathematics

The following keywords cover all fields of mathematics, specific topics that are related to math, etc.

1-dimensional cellular automata

MIT Mystery Hunt 2018 The Next Generation

3SAT (boolean satisfiability problem)

MIT Mystery Hunt 2014 SAT III

accounting

MIT Mystery Hunt 2007 Earnings Call
MIT Mystery Hunt 2011 Wall Street Meta
MIT Mystery Hunt 2014 Growth and Fixed Costs
MIT Mystery Hunt 2018 Harsh Financial Scrutiny

Aksharapalli number system

System of numbers used in old texts from India, commonly for numbering pages of a text, using certain syllables (in the script of the text) to indicate each number.

MIT Mystery Hunt 2023 To Numbers and Back Again

algorithmic complexity

MIT Mystery Hunt 2021 Complexity Evaluation

The standard form of this puzzle type is a list of words, along with their values in a cipher which applies a different value from 1 to 26 to each letter of the alphabet, and adds up the values of the letters in each word. It's similar to an alphametic but there's no interaction of place value, and usually the whole alphabet is used.

MIT Mystery Hunt 1994 22

alphacode

See Alphacipher

alphametics (encoded arithmetic)

These puzzles are essentially solved arithmetic problems (often long division or multiplication with all the partial products written out), with the entire problem encoded into letters with a simple substitution cipher. Sometimes the key (what 0123456789 encodes into) spells a final answer. A variant sometimes seen uses stars or blanks to indicate unknown digits.

angles

MIT Mystery Hunt 2023 Broken Wheel

Aztec numerals

See Mayan/Aztec numerals

Babylonian numerals

MIT Mystery Hunt 2004 A Scholarly Lesson

balance puzzle

The standard form of this puzzle includes a set of two or more hanging beams marked off in equally spaced intervals, with weights and/or other beams hanging at some of the marked points. This structure, a bit like a mobile, is meant to balance by the torque rule - for each beam, the sum of (weight x distance to fulcrum) for all weights on one side of the fulcrum equals that sum for the other side, the fulcrum in this case being the point the beam hangs from. The beams themselves are weightless but convey the total weight of the weights they hold to the beam they hang from. The values of the weights must be filled in from a predetermined set, usually 1 to N where N is the number of weights.

MIT Mystery Hunt 1995 20: Art Gallery

base 20

Base 20 numbers are most commonly encountered in the Mayan numeral system.

MIT Mystery Hunt 2010 Counter Culture
MIT Mystery Hunt 2022 Diced Turkey Hash

base 36

Sometimes seen as the ultimate number base since it uses all the standard numerals and letters as digits. Of course, it isn't, but it takes more creativity or care to write numbers in larger bases clearly.

MIT Mystery Hunt 1996 11B
MIT Mystery Hunt 1996 Endgame
MIT Mystery Hunt 2015 Pipe
MIT Mystery Hunt 2022 Lists of Large Integers

base 5

The base 5 numeral system. This is sometimes used as a way of encoding the alphabet in two-character blocks, though since it has only 25 values, one letter must be left out.

MIT Mystery Hunt 2006 Syncopation
MIT Mystery Hunt 2013 Plead the Fifth

bases other than ten

These puzzles use uncommon or many bases. See also:

Bhutasamkhya system of numbers

A system of writing numbers in Sanskrit using nouns associatd with the number, such as eye for two because a person has two eyes.

MIT Mystery Hunt 2023 To Numbers and Back Again

binary

The base 2 numeral system, the basis of storing numbers in most computers. See also all forms of 5-bit binary alphabets and ASCII.

MIT Mystery Hunt 1982 Subclue #14
MIT Mystery Hunt 2013 Substance Abuse
MIT Mystery Hunt 2020 Story
MIT Mystery Hunt 2020 Ox (Bull)
MIT Mystery Hunt 2022 Diced Turkey Hash

building 2 mathematical models

(a display case on the first floor)

MIT Mystery Hunt 2011 Showcase
MIT Mystery Hunt 2020 Catenoid

busy beaver Turing machines

MIT Mystery Hunt 2013 Halting Problem

calculatrivia

Long ago, back before the Internet made hard trivia easy and impossible trivia doable, Games magazine ran a series of contests which consisted of nothing but a zeries of trivia questions whose answers were all numbers and a complicated equation to plug all the numbers into.

MIT Mystery Hunt 1998 18.617 Number Theory
MIT Mystery Hunt 2016 Trivial Mathematics
MIT Mystery Hunt 2021 Exactly

Cartesian coordinates

MIT Mystery Hunt 2014 Modern Cubism Artist
MIT Mystery Hunt 2014 Crosswalks
MIT Mystery Hunt 2016 Luminance Shift
MIT Mystery Hunt 2017 . . . Or Don't We?
MIT Mystery Hunt 2017 Pentoku
MIT Mystery Hunt 2023 4D Geo

characteristic polynomial

A polynomial whose roots are the eigenvalues of a given square matrix.

MIT Mystery Hunt 2022 Tryst of Fate

Cherokee numerals

MIT Mystery Hunt 2023 North Carolina Shopping List

Cheryl's Birthday problem

This is a kind of information deduction problem. Two people are each given incomplete information about some fact (in the original, the month and day of Cheryl's birth) and they make statements which progressively reveal more information to the other. Both the solver and the other character make deductions based on the idea that when one character does not know something, it means there are still two possibilities with all the information that character knows (including half the answer).

MIT Mystery Hunt 2021 Ignorance
MIT Mystery Hunt 2022 Strange Garnets

Chinese numerals

MIT Mystery Hunt 2012 Encoded
MIT Mystery Hunt 2016 Pictocryptolists

Chinese remainder theorem

MIT Mystery Hunt 2008 All Geared Up
MIT Mystery Hunt 2009 Round 9 Meta
MIT Mystery Hunt 2013 Czar Cycle
MIT Mystery Hunt 2021 One Size Fits All

completing the square

Completing the square is a mathematical concept used with polynomials. Given a polynomial such as x²+2x, you add a 1 to make it a square (in this case, (x+1)².

MIT Mystery Hunt 2016 You Complete Me

complex numbers

MIT Mystery Hunt 2021 Just Index
MIT Mystery Hunt 2023 Period of Wyrm

context-free grammars

A set of rules used to define a set of strings.

MIT Mystery Hunt 2018 No Context

Conway's Game of Life

See Life (cellular automaton)

counting shapes

MIT Mystery Hunt 2010 Counter Culture
MIT Mystery Hunt 2012 My Summer Vacation

cross-number puzzle

This is a crossword puzzle where the answers are numbers written with digits. These puzzles are usually full of cross-references and clues which limit their answers to certain subsets of integers, and usually follow the rule (as in many numerical puzzles) leading zeroes are not allowed.

MIT Mystery Hunt 1997 Two MIT Students Claim Elvis Was Their 6.001 TA!
MIT Mystery Hunt 2012 QED
MIT Mystery Hunt 2023 Lost to Time

Cross Products (Cross Sums variant)

This is like a Cross Sums except the product of the digits in each entry is given, rather than the sum.

MIT Mystery Hunt 2008 Cursed
MIT Mystery Hunt 2024 Why The Romans Never Invented Logic Puzzles

Cross Sums

This is one of the most popular numerical puzzle types. In its standard form, a crossword-like grid has clues in the grid providing the sum of the digits to be entered in each entry. No zeroes are used and no entry contains any digit more than once.

MIT Mystery Hunt 2001 23
MIT Mystery Hunt 2003 Some Stars
MIT Mystery Hunt 2005 Express Yourself
MIT Mystery Hunt 2007 The Joy of Accountancy
MIT Mystery Hunt 2009 Cross Something-Or-Others (numerous variations)
MIT Mystery Hunt 2011 Technological Crisis at Shikakuro Farms (variant)
MIT Mystery Hunt 2012 The Signs They Are A-Changin’ (variant)
MIT Mystery Hunt 2014 Kroskuro
MIT Mystery Hunt 2017 Stackuro

cryptarithms

See alphametics (encoded arithmetic)

cube nets

The hexominoes which you can get by unfolding a cube along its edges into a flat shape.

MIT Mystery Hunt 2017 The Curious Cube
MIT Mystery Hunt 2018 Blocked Lines
MIT Mystery Hunt 2023 Error: File "txtadv.py" not found

Cuneiform numerals

MIT Mystery Hunt 2004 A Scholarly Lesson

cutting out shapes

(most, but not all, of these involve cutting out shapes to fold into 3-dimensional figures)

D'Hondt allocation method

MIT Mystery Hunt 2022 The Hound of the Vast-Cur-Villes

dimension added

(any puzzle that takes a standard puzzle type and adds more dimensions than it usually has)

dissection (geometric)

MIT Mystery Hunt 2000 Hot Shots
MIT Mystery Hunt 2013 Lost in Translation

D'ni numerals

MIT Mystery Hunt 2006 Numeracy

ellipse

MIT Mystery Hunt 2020 FOCUS!!

elliptic curves

MIT Mystery Hunt 2020 Torsion Twirl

Encyclopedia of Integer Sequences

MIT Mystery Hunt 2000 Everything Is Something
MIT Mystery Hunt 2012 20 Questions
MIT Mystery Hunt 2018 Cash Cab

factorization

MIT Mystery Hunt 2005 Ginormous
MIT Mystery Hunt 2006 Hey, Look, a Grid!
MIT Mystery Hunt 2007 Round VI Meta
MIT Mystery Hunt 2011 Another Small Collection of Immense Integers
MIT Mystery Hunt 2012 20 Questions
MIT Mystery Hunt 2013 Halting Problem
MIT Mystery Hunt 2016 Replication
MIT Mystery Hunt 2022 Lists of Large Integers

Fermat's Last Theorem

MIT Mystery Hunt 2013 Halting Problem

Figure Logic puzzle

See cross-number puzzle

Financial Chinese

The characters normally used for writing numbers in Chinese are easy for a forger to manipulate by adding strokes to change the numbers into other numbers. To prevent this, another system of writing numbers is used in financial contexts which are more complicated and not easy to manipulate in this way.

MIT Mystery Hunt 2006 Numeracy

finite fields

MIT Mystery Hunt 2013 Agricultural Operations

fractals

MIT Mystery Hunt 2005 Maze
MIT Mystery Hunt 2013 In the Details
MIT Mystery Hunt 2020 Backlot
MIT Mystery Hunt 2020 Snowy Flow
MIT Mystery Hunt 2021 Simmons Hall
MIT Mystery Hunt 2023 The Legend
MIT Mystery Hunt 2023 Period of Wyrm

frequency distributions

MIT Mystery Hunt 2008 Picture Store
MIT Mystery Hunt 2013 50/50
MIT Mystery Hunt 2015 Frequency Distribution Tank
MIT Mystery Hunt 2021 Random Hall

Game of Life (cellular automaton)

See Life (cellular automaton)

game theory

MIT Mystery Hunt 2011 Games
MIT Mystery Hunt 2022 A Number of Games

geometry

MIT Mystery Hunt 1999 Beirut
MIT Mystery Hunt 2018 X Marks the Spot
MIT Mystery Hunt 2018 Floor Drawing 305
MIT Mystery Hunt 2019 Compass and Straightedge
MIT Mystery Hunt 2019 Polyphony
MIT Mystery Hunt 2020 FOCUS!!
MIT Mystery Hunt 2021 Squaring the Circle
MIT Mystery Hunt 2023 Solve for Ewe

Godel, Escher, Bach: An Eternal Golden Braid

MIT Mystery Hunt 1996 1C
MIT Mystery Hunt 1996 4B
MIT Mystery Hunt 1996 7B
MIT Mystery Hunt 1996 10C
MIT Mystery Hunt 1996 Gödel meta

googology

Googology is the study of enormous numbers, ones so big you can't write them out, and especially ones so big you can't even write the number in scientific notation, so towers of exponents or even more esoteric notations are required to write the numbers.

MIT Mystery Hunt 2016 identify, SORT, index, solve

graph theory

MIT Mystery Hunt 2019 Cubic
MIT Mystery Hunt 2020 Star Maps
MIT Mystery Hunt 2021 Complexity Evaluation
MIT Mystery Hunt 2022 Wooded Path

greatest common factor

MIT Mystery Hunt 2023 The Runaround

group theory

MIT Mystery Hunt 2015 Representative Characters
MIT Mystery Hunt 2017 Great Tits!

Hamiltonian paths

MIT Mystery Hunt 2022 How To Make a Loop

Hebrew gematria

MIT Mystery Hunt 2012 Encoded

Hebrew numerals

MIT Mystery Hunt 2022 Once is Happenstance
MIT Mystery Hunt 2022 Head for the Kitchen

hexadecimal

The base 16 numeral system, very commonly used in computing as a way to write bytes in only two characters.

MIT Mystery Hunt 2005 Seven Days
MIT Mystery Hunt 2008 Cursed
MIT Mystery Hunt 2012 Tax... In... Space
MIT Mystery Hunt 2014 Apocalypse
MIT Mystery Hunt 2015 Image
MIT Mystery Hunt 2019 Twisty Passages
MIT Mystery Hunt 2021 A Bit of Light
MIT Mystery Hunt 2023 Graffiti
MIT Mystery Hunt 2023 A Conspiracy Network
MIT Mystery Hunt 2023 Pixel Art

huge numbers

MIT Mystery Hunt 2016 identify, SORT, index, solve
MIT Mystery Hunt 2017 Digital Display
MIT Mystery Hunt 2021 1000000000000000000000000000000000000000000000000000000000000000000001000000000000116
MIT Mystery Hunt 2022 Lists of Large Integers

Indian numerals

MIT Mystery Hunt 2004 Fabrics Booty Meta

integer sequences

MIT Mystery Hunt 1996 4C
MIT Mystery Hunt 2012 Betsy Johnson Meta
MIT Mystery Hunt 2012 20 Questions
MIT Mystery Hunt 2013 Integers and Sequence
MIT Mystery Hunt 2016 You Complete Me
MIT Mystery Hunt 2023 Brain Freeze

International Math Olympiad (IMO)

MIT Mystery Hunt 2021 The IMO Shortlist

intersections

MIT Mystery Hunt 2014 Crosswalks
MIT Mystery Hunt 2015 Funny Shapes
MIT Mystery Hunt 2018 Zelma & Frank

isomorphic graphs

MIT Mystery Hunt 2012 Course 7E
MIT Mystery Hunt 2013 Git Hub
MIT Mystery Hunt 2020 Horse
MIT Mystery Hunt 2023 Conjuri's Request

Javanese numerals

MIT Mystery Hunt 2006 Numeracy

Julia sets

MIT Mystery Hunt 2019 Rules of Order

Kakuro

See Cross Sums

knight's tour

As a purely mathematical puzzle, this is simply a challenge to cover each square of a grid once with a series of knight moves (as in chess). But more commonly this same sort of knight's tour occurs on a grid pre-filled with letters, so that words are spelled out along the path.

MIT Mystery Hunt 1994 28
MIT Mystery Hunt 2008 This Puzzle Needs a Title
MIT Mystery Hunt 2010 The Arena
MIT Mystery Hunt 2019 Art Tours
MIT Mystery Hunt 2020 Chairiot Races
MIT Mystery Hunt 2022 Board Members

knot theory

MIT Mystery Hunt 2008 Knots and Crosswords
MIT Mystery Hunt 2013 Slinking Slumber
MIT Mystery Hunt 2014 Please Remain Seated
MIT Mystery Hunt 2022 How To Make a Loop
MIT Mystery Hunt 2023 Endless Knots

Lao numerals

MIT Mystery Hunt 2006 Numeracy
MIT Mystery Hunt 2016 Pictocryptolists

Life (cellular automaton)

MIT Mystery Hunt 1996 12C
MIT Mystery Hunt 2001 Helminthophobia
MIT Mystery Hunt 2006 Get on with It (also Life cereal, Life magazine, Hasbro's Game of Life)
MIT Mystery Hunt 2007 Creature Discomforts
MIT Mystery Hunt 2008 Tragedy
MIT Mystery Hunt 2011 The Eternal Struggle
MIT Mystery Hunt 2013 Mind the Gaps
MIT Mystery Hunt 2019 New Year's Town/Patriots' Day Town Meta
MIT Mystery Hunt 2021 Escape from Life
MIT Mystery Hunt 2023 Diagramless

logical operators

MIT Mystery Hunt 2012 Ben Bitdiddle's Review
MIT Mystery Hunt 2014 Thank Heaven for Little Girls
MIT Mystery Hunt 2017 False Prophets
MIT Mystery Hunt 2023 World's Largest Logic Puzzle

magic squares

MIT Mystery Hunt 2012 Twosquare
MIT Mystery Hunt 2013 W♄ite Magic
MIT Mystery Hunt 2014 A Puzzle with the Answer I WANT TO HOLD YOUR HAND

math

mathematicians

MIT Mystery Hunt 2023 Overloaded

matrices

MIT Mystery Hunt 2006 Disarray
MIT Mystery Hunt 2009 Interstellar Basic Algebra

Mayan/Aztec numerals

MIT Mystery Hunt 2006 Numeracy
MIT Mystery Hunt 2022 Diced Turkey Hash
MIT Mystery Hunt 2023 Graffiti

midpoints

MIT Mystery Hunt 2015 I Know That's a Pisser Baby
MIT Mystery Hunt 2018 Middle of the Road
MIT Mystery Hunt 2022 How To Install a Handle
MIT Mystery Hunt 2023 Make Love or War

Mobius strip

MIT Mystery Hunt 2009 Welcome to Probistis Mu
MIT Mystery Hunt 2012 Strip Mind
MIT Mystery Hunt 2018 Message in a Bottle
MIT Mystery Hunt 2021 Slitheɹlᴉuʞs

nim

Nim is a mathematical game. The basic version has several piles of chips, and each player in turn picks any pile and removes one or more chips from that pile (including possibly taking the whole pile). There are many variations of the game and a whole area of mathematics based on finding the best strategies for these games.

MIT Mystery Hunt 1996 2B
MIT Mystery Hunt 2017 On Numbers and Games
MIT Mystery Hunt 2019 Bubbly