XMind

Recreational Maths

1. Chessboard-related

   1. Tiling Dominoes

   2. 15-Puzzle

   3. Knight Tour

   4. 8-Queen Puzzle

   5. Magic Squares

      1. 2n-1

      2. 4n

      3. 4n+2

2. Cube-related

   1. Langford Problem

   2. Instant Insanity

3. River Crossing Puzzles

   1. Bridge and Torch Problem

   2. Missionaries and Cannibals Problem

   3. 4 Jealous Husband Problem with Island

   4. Fox, Goose and Bag of Beans Problem

   5. Father, Mother, 2 Sons, 2 Daughters, Policeman and Thief Problem

4. Balance-related

   1. 1 Fake Coin in 9 Coins, Lighter/Heavier Known

   2. 1 Fake Coin in 9 Coins, Lighter/Heavier Unknown

   3. 1 Whole Pile of 10 Piles of Coins Lighter/Heavier

   4. Unknown Bottle(s) of 10 Bottles of Pills Lighter/Heavier

5. Alternative Proofs

   1. Combinatorial Proof

6. Optimization

   1. Stable Marriage Problem

   2. Secretary Problem

   3. Geometrical Optimization

      1. Heron's Shortest Path Problem

      2. Building Bridge Problem

      3. Fagnano's Problem

      4. Shortest Fence for Halving Triangular Field

7. Paradoxes

   1. Missing Dollar Riddle

   2. Missing Square Puzzle

   3. Inheriting 17 Horses Paradox

8. Speed Arithmetics

   1. Algebraic Identities

   2. 24 Game

      1. 5.5.5.1

      2. 3.3.8.8

9. Handful Maths

   1. Handcuff Puzzles

   2. Mobius Strips

   3. Large Hole in a Small Piece of Paper

   4. Linking Paperclips

   5. Human Knots

   6. Origami

      1. Flexagon

      2. Cootie Catcher

      3. Polyhedra

10. Visual Maths

    1. Napier's Bones

    2. Visual Multiplication

    3. Dissection Proof

       1. Triangular Number

       2. Square Number

    4. Pascal Triangle

    5. Fibonacci Number

11. Network-related

    1. 7 Elevators Stop at 6 Floors

    2. Rigid Braced Framework

    3. 3 Utilities Puzzle

    4. 9 Dots Puzzle