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Score of 6
1 answer
51 views

Diophantine ___ given by date ___ of hyperbola $\frac{x^2}5-\frac{y^2}{6e^2}=1$ Volume of regular ___ with edge length $\frac{2^\varphi}e$ ___ constant, typographically ___ of vector $(\ln2,\sqrt2,e)$ ...
Score of 3
1 answer
55 views

This is, oddly enough, a true story. Making a square out of squares. Many years ago, I was playing around with some semaphore flag squares (two triangles, one white, one coloured) and wondered what ...
Score of 4
1 answer
81 views

Uh oh! My girlfriend is mad at me for flaking this weekend. She left me this note in my mailbox this morning: Just who do you think you are! Usually, as you know, I can forgive your thoughtlessness ...
Score of 7
2 answers
236 views

A convex subset of a triangular grid is the union of some triangles in the grid that together form a convex subset of the plane. When can you tile such a subset with lozenges (60°-120° rhombi)? Below ...
Score of 11
2 answers
437 views

19 July is National Ice Cream Day. To celebrate, I've made a few "Scramblegories"1 puzzles. Each has a series of four-letter words. You must make four ice cream flavors2, each of which takes ...
Score of 21
1 answer
318 views

This puzzle is part of Monthly Topic Challenge July 2026: Obscure Observances. Move a square in the right column up by one. What Braille letter is this? Rotate the image so the extra square is on top....
Score of 6
1 answer
197 views

This puzzle is based off the [What is a Word™] series started by JLee If a word has a certain property, I call it a Neutralized Word. If not, I call it a Non-Neutralized Word. Use the examples below ...
Score of 8
1 answer
294 views

This is part of the Monthly Topic Challenge for July 2026. It is also an original puzzle, so errors may have been made (I do check these, but I am not perfect, thanks in advance for your understanding)...
Score of 7
5 answers
702 views

Given two identical sheets of standard-sized A4 paper and a ruler marked to the centimeter, devise a procedure for measuring the thickness of a sheet of paper to ±10% accuracy. This procedure must be ...
Score of -4
1 answer
117 views

There were 5 members in a family with a dog and a cat. One day a killer (might be an animal or human or robber) entered the house to kill somebody and found in the kitchen eating ketchup of blood the ...
Score of 2
2 answers
321 views

This is a true story. I know the answer (I worked it out at the time) but I think it is an interesting puzzle, worth sharing here Last week I was discussing random probability facts with colleagues (...
Score of -1
0 answers
95 views

In the puzzle "The Hardest Logic Puzzle Ever", what if I ask the first person, "What would the second person answer if I asked them a certain question?" I understand that they all ...
Score of 8
1 answer
343 views

To get the answer, you have to do something. What do you have to do? Hint 1
Score of 5
3 answers
575 views

Catching up for drinks. Four old school friends made plans with me next month on the 2nd, 4th, 6th and 8th of the month to catch up for a glass of wine (or bottle, or two…) The friends names are Angus,...
Score of 8
1 answer
331 views

This puzzle is part of Monthly Topic Challenge July 2026: Obscure Observances. Solve these eleven cryptic clues to figure out our harvest. The clues are ordered such that their answers are ordered ...

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