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In the diagram below, there are two types of L-shaped pieces (one made of 5 unit squares and the other made of 7 unit squares). The goal is to tile a 6x9 rectangle with one or more of the smaller ...
Find three different integers A, B and C such that A+B, A+C and B+C are all powers of 2. Clarifications: A, B and C can be negative, zero or positive. Powers of 2 are: 1, 2, 4, 8, 16, ...
Do they have an alert system or the site owner are likely have to detect themselves and report to the vendor? How do they fix the problem? And do they do that for free? As the site owners are their...
Draw 8 straight line segments so that each line segment intersects with exactly 3 other line segments.
Consider the following L-shaped 3-dimensional object consisting of 3 unit cubes joined at their faces: Is it possible to use six of the above L-shaped pieces to form the following 3-dimensiona...
There are $146$ marbles in a bucket. Delta and Epsilon play a game in which they take turns removing marbles from the bucket with Delta going first. At each turn the player can choose to remove e...
There are $100$ marbles in a bucket. Alpha and Beta play a game in which they take turns removing marbles from the bucket with Alpha going first. At each turn the player can choose to remove eith...
Consider the following L-shaped 3-dimensional object made up of three unit cubes joined at their faces: Puzzle 1. Use 9 of the above L-shaped pieces to make a cube. Puzzle 2. Use 10 of the ...
This post describes a classic puzzle. If you have previously seen this puzzle I request that you allow someone else to solve it and post their answer. Thank you! Mutilated chessboard problem: ...
So I was designing this superhuman criminal whose largely just a common burgler. As I was designing her and her powers, eventually I thought of the idea of batwings on the back largely because I th...
A number $\large X$ is defined to be a Droppable Square number if the ordinary base-10 representation of $\large X^2$ can be formed by inserting the digit $\large 2$ anywhere in the base-10 represe...
Consider the following L-shaped piece made of three unit squares joined at their edges: Allowing rotations of the L-shaped pieces, you can easily tile a 2x3 rectangle with two of the above L-sha...
What does the following image represent? Description of above image for those who can’t view it: On the left: Horizontal line with a green happy face above it and a green letter K below it. ...
Join the pairs of dots marked similarly (i.e. A to A, B to B, etc.) using four lines which do not cross or touch at any point. The routes must follow the lines of the grid, and may not pass through...
My fifth is an organ, it's revelatory, My sixth from a slitherer telling its story. My first lacks aspiration but's bringing it still, You’re half way to working this out if you will. My third ...
Puzzle How short can you make a closed knight’s sightseeing tour? Terminology Standard terminology A chess board is an 8 by 8 chequerboard. A knight is a chess piece that moves 2 squares hor...
Draw 3 lines, not necessarily straight, connecting the dots and satisfying all the following conditions: No line may touch or intersect another line. Every line must be completely inside the ci...
In each puzzle, fill the circles using all the positive integers 1, 2, 3, ... n, where n is the number of circles in such a way that consecutive numbers are NOT in circles that are joined with a li...
Here’s a cute puzzle you can share with children. Can you find the intruder?
Fill all 16 squares with a number so that every row, every column and every 2x2 box contains all the numbers 1, 2, 3 and 4 each exactly once. Also the sum of the numbers in the six squares marked ...
Fill each empty square with a number so that every row, every column and every irregularly shaped region contains all the numbers 1, 2, 3, 4 and 5 each exactly once. If you enjoyed this puzzle...
Draw a straight line through the center of the circle below to subdivide it into two halves so that each half will have the same number of occurrences of the letter A. Also each half will have the...
Three perfectly logical women, one of them blind, walk into a completely dark room full of hats. They all know that two of the hats are red and the rest are black. Each woman randomly selects...
A blind person is handed a deck of 52 playing cards and told that exactly 10 of these cards are facing up. How can they divide the cards into two piles, not necessarily of equal size, with each...
Find the pattern in the fingers:
Place the 9 tiles in the 3 by 3 grid. The curved lines on the tiles must divide the grid. The regions the grid is split into must contain equal numbers of dots. The curved lines may stop at th...
Place each of the 9 tiles into the 3 by 3 grid of squares. Each tile may be rotated by any multiple of 90 degrees. Each line on each tile must either meet the edge of the grid or be matched aga...
Arrange the 9 tiles in a 3 by 3 grid so that the lines on them have no loose ends. A line may leave the edge of the grid provided it rejoins on the opposite edge at the same position (the same h...
Arrange the provided polyominoes on a 5 by 5 grid of squares so that there are zero empty squares. The grid The grid is composed of 25 empty squares, arranged in 5 rows and 5 columns. The poly...
Grid This puzzle is played on a 5 by 5 grid of squares: Tiles There are 25 tiles to be placed on the grid, one on each square. They can each be rotated by any multiple of 90 degrees. Note ...
The area of a triangle can be calculated as half of the length of its base multiplied by its perpendicular height. This means that two triangles with the same length base and the same perpendicular...
For each of these Make 24 puzzles, use each of the four given numbers exactly once, combined only with addition, subtraction, multiplication, or division to make an expression whose value equals 24...
What number belongs at ? in this sequence? 24 28 33 34 32 36 35 46 52 53 13 11 17 16 18 14 22 ? 33 19 24 Attribution: Nob Yoshigahara in The Mathemagician and Pied Puzzler A Colle...
What part of Toronto is in Peru?
If from six you take nine, and from nine you take ten, (You youths, now the mystery explain;) And if fifty from forty be taken, there then Shall just half a dozen remain. The above puz...
Make a mathematical expression whose value is equal to $2$ that uses all the digits $0, 1, 2, \ \cdots, \ 9$ each exactly once and uses as few other mathematical symbols as possible. Clarification...
A 6x6 checkerboard is tiled arbitrarily with eighteen 1x2 dominoes. A new square is added to the right-hand side of the board, making the top row length 7. At any time you may move a domino from i...
What do you call a tiny psychic that’s wanted by the police?
Given 2 bags and 5 stones, how would you place the stones into the bags so that the following three conditions are met: Both bags contain an odd number of stones. Every stone is inside a bag. ...
Which positive integers N have the property that there exists at least one positive integer multiple of N such that the base 10 representation of that multiple has only odd digits? Examples: $103...
Using all the integers from 1 to 10 inclusive (each used exactly once), along with any number of the four arithmetic operations (add, subtract, multiply and divide) and parentheses, construct an eq...
Imagine you are on a planet the same size as Earth but this planet is perfectly spherical and solid everywhere. Furthermore assume it has a North and a South Pole just like Earth and has direction...
In the image below, nine toothpicks have been arranged to form the number 100. Can you move two toothpicks to form the word CAT. Attribution: Martin Gardner
Sometimes after I solve a Wordle puzzle I'll see what their bot had to say about my solution. Occasionally one of my words is a legitimate five-letter word (accepted by Wordle) but the bot says so...
The time is 8:59 or ... Where is the large cook promotion? Note: The correct answer to this puzzle is related to the numbers 3,4,2. Spoiler! Click here to reveal a hint about fillin...
Warmup puzzle: Here is an astronomical study for the little folks, although it may puzzle the grown ups as well. See how long it will take you to discover a perfect star in the above general mix...
Canoe, Wrote, Teacher, Runoff, Verify, Exist, Inverse, Tighten, ? What meal can come next in the above list? Choose your answer from the options below and explain your choice: Breakfast, Brunch,...
What 7-letter word does the following rebus represent?
While rewatching Stargate Atlantis I noticed someone, I believe it was Carson Beckett, wearing a wristwatch. This made me wonder: How do they manage time in Atlantis? I remember someone saying tha...
There are 8 binary strings of length 3. They are: 000 001 010 011 100 101 110 111 The goal of this puzzle is to arrange some 0’s and some 1’s around a circle (using as few 0’s and 1’s as ...
