# All Questions

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### Pythagorean triangle dissection

This is a variation of Pythagorean quilts. I will make it short, this time. Pythagoras's theorem also works for triangles. This leads to following the variation: Dissect the triangles of size 5 and ...
23 views

### Words with a letter sound at the start but not the letter

Here is a fun little word puzzle. The task, for as many letters of the alphabet as possible, is to find words that have the sound of the name of a letter at the start but which don’t start with that ...
44 views

### Lost Bearings: A Puzzle That I've Designed

I'm Benjamin Curran. I'm a 14 year old puzzle lover and I come to you with this puzzle that I've made up myself. Hopefully you won't find it tricky. Two tourists have gotten themselves lost in the ...
78 views

### Catching the Vegetable-Goose

After an altercation involving giant bees, you have been sentence to some hard labour, specifically harvesting barnacle-lambs: a gourd-like fruit that grows geese in its shell While working, you get ...
79 views

### Puzzling rectangles [closed]

Can you find two unequal rectangles whose areas add to $5\sqrt5$? No computer solutions please.
523 views

### Heteropalindromes in a Word Square

Say hello to a not-so-simple, 4x4 word square: This little monstrosity has two rules; to define the first rule, have you ever heard of a heteropalindrome? Strings of letters that form words when ...
118 views

### How many Hoshi (Star Sudoku) are possible?

A gifted Sudoku booklet's Hoshi are (almost? - I did only spot checks) all identical, except for number permutation and leads. An excuse for this would be if there were only one legit Hoshi. How many ...
107 views

### How do I ring my friend's doorbell?

My friend, a curmudgeon who dislikes visitors, recently installed a puzzle-doorbell. It consists of ten push buttons in a row, labelled from left to right: ...
116 views

### Not really seen - what am I?

Half of me is all the same. The other half is just a proposition. When I'm observed, I'm not really seen. Probably because I'm in full opposition. Hint:
127 views

### How fast can you ruin a Scrabble game?

Consider a standard game of Scrabble® using the csw19 dictionary. Many board-states exist where ZERO possible next moves exist. That is, no combination of 1-7 remaining letters can make a legal move. ...
722 views

### A Perfect Diamond of Numbers

A diamond of numbers is an arrangement of circles in the shape of a trapezoid (see figure) in which the number in any circle above its central (longest) row is the sum of the two numbers in the ...
215 views

### A Station Story

A friend of mine who works with computers sent me this handwritten short story in the post with no explanation whatsoever. It raises many questions, for one he usually just emails me, and he's never ...
108 views

### An everyday object... but it's a Really Obvious Problem Everyday

None of me and things might fall Things also can't move, as I recall Part of me, and you are me All of me, might determine your fate, After all, you would be under constraint I am a 4 letter word. ...
94 views

### The blade of the leaf

Given a bird, a cat and a shrew, along with a bat to give you a few. Some sleep at night, others in light, surprisingly you are one too. How do you relate to the title?
2k views

### Spiders on a cube

Two spiders are trying to catch an ant. All are constrained to move along the edges of a transparent cube. The speed of the ant is $1$. The speeds of the spiders are $v_1$ and $v_2$ respectively. What'...
184 views

### Mysterious Deaths, or is it just a well known attack?

Last week you were promoted to the position of Sergeant Head Detective of Australia, which basically means the best detective in Australia. Its January 2019, and you wake up ready for your new job. ...
146 views

### The Turing Test "It doesn't Add Up question" [closed]

In the square below, change the position of six numbers, one per horizontal row, vertical column and long diagonal line of six smaller squares, in such a way so the numbers in each row, column or ...
420 views

### Can you guess? You won't be able to answer!

I am Half of nothing Part of one More or less Favorite of children But fully a villain! Can you guess this word?
1k views

### It's a LITS! And a... um...?

I've combined two of my favourite puzzle types - a LITS grid-deduction puzzle and a, er... a, um... you know, I could have sworn I wrote it down here somewhere! Click on the image for a resolution ...
794 views

### 9x9 Vanilla Tapa

Rules of Tapa: Shade some cells so that all shaded cells form one orthogonally connected area. Clues cannot be shaded and represent the lengths of the shaded cell surrounding that clue. If there are ...
351 views

### Coin Flipping Puzzle

This is a repost from my post at Math Stack Exchange 2 criminals A and B, were recently captured and brought to prison. They were then locked in two separate rooms. Known for being exceedingly smart, ...
218 views
+50

### Squares and chords in a circle

The whole numbers 1 to 2n are placed in order around a circle. For which n is it possible to draw n non-intersecting chords (one from each number) such that each of them joins two numbers whose sum ...
172 views

### An unusual source of inspiration?

In each row of the table below, a word* is missing (in Column B). This word can be paired separately with the two either side of it (in Columns A and C) to form another English word or phrase, ...
2k views

### The Thieves and the Gold Bars

Two thieves (Rod and Lia) carry out a big heist and steal 16 gold bars. They get away in their car when they run into a bad accident and the car is completely wrecked. Luckily they survive with their ...
69 views

### Who owes what and to whom [closed]

There are 3 people involved: A M and H The total cost of a bar bill is £379.00 A and M each stayed in the hotel for 7 nights each H stayed for 4 nights A paid £283.00 M paid £96.00 H paid 0 If the bar ...
137 views

### What is something you can take from another, but if you do, then no one has it? [closed]

What is something you can take from another, but if you do, then no one has it?
719 views

### Most points on a circle

What is the most number of integer lattice points that lie on the circumference of a single circle whose radius is 80 or less? Please no computer computations.
1k views

### Tiling with Js and Ls

In this puzzle you must tile the plane with identically sized colored L and J tetraminos. To start I will place two of them like so: Your task will be to tile the entire rest of the plane meeting ...
253 views

### A special kind of thank you

I typed up a thank you message this morning, but I accidentally ran a cipher on it and can't remember how to unscramble it. vh 5cq pajmn lujbbaxxv fjclqrwp cnaaxa dwoxum xw cqn cnunerbrxw. R anvnvkna ...
88 views

### Four-Letter Blocks: Nursery Rhymes (15x15)

I've designed a new type of puzzle called Four-Letter Blocks that mixes crossword puzzles with jigsaw puzzles. You are given a crossword puzzle that's been filled in and then cut up into blocks of ...
221 views

### What number comes next in 2, 4, 5, 3, 10, …

2, 4, 5, 3, 10, 11, 13, 7, 5, 28, 29, 31, 35, ??? I tried plugging it into Wolfram Alpha which couldn't find any pattern, and I'm still not too sure how to determine what number comes next. Any ideas?...
213 views

### Doing Time In Prison

A prisoner was awoken by an earthquake that caused his wall clock to fall to the floor and rolled in the corner of his cell. When the ground stops shaking, he learns that the clock is still working ...
166 views

### They say that I am sexy - who am I?

Who am I? They say that I am sexy And that I'm a lady I have four syllables Only when said slowly
252 views

### Two different colors

The answer to this puzzle is a word.
139 views

### How many liars were there at the party? [duplicate]

Andy’s birthday party has just been moved up by a week. All the toys in Andy’s room are worried about being replaced by fancy new toys. Sheriff Woody, Andy’s favourite toy, and the others are waiting ...
140 views

### Finding the path on a hexagonal playground?

Ben is at school playground. The playground is a special playground though: Its in a form of a hexagonal grid, and each hexagonal spot has a number. Ben loved the playground, and was even more eager ...
111 views

### Smallest Autonumerogram

An autonumerogram consists of digits and their counts, counts always appeared immediately before the corresponding digit, and no digit and its count were repeated or overlapped. For example: 22 has 2 ...
377 views
+50

### Why is it growing?

Once you have looked at it, I become more. Once you give it to others, I become more. Some people boost if I become more. Some people even get money if I become more. If I am more, everybody talks ...
297 views

### Criminals and lawsuits

Across 1. Merely suitable or exactly right (4) 4. Throw dance party after Lent? (8) 10. Happening near Alberto Fujimori's home: Eating shaved ice with the last bit of fruit punch (8) 12. Share load of ...
235 views

### Arrange the wooden blocks in the box

Little Johnny is the naughtiest child in the kindergarden today. The kind who always wants more than the other children. When he saw that little Tim was playing with the same set of wooden blocks as ...
1k views

### A pretty binary grid 👾

What will I be doing this weekend? For convenience, I'm also providing the grid in text form:
442 views

### Catch the angel in less than 7 units of time

The devil has trapped the angel in a regular hexagram of firewalls. The perimeter of the hexagram is 12. The devil starts at the apex of the hexagram. can move at speed $1$ to leave a trajectory of ...
175 views

### What is the name of this toy game having seven discs with six stones

I do not remember where I have it from, it might well date from the pre-internet age. I guess the discs can be interchanged and the stones not. Now, that you got this valuable hint, it is your turn ...
2k views

Tired of solving Sudokus on paper? Look no further! The solution is, literally, under your nose. Why use a 9x9 grid, when you can use your own QWERTY keyboard! RULES: Fill each row with the numbers ...
6k views

### Prove that sin(x) ≥ x/2, but without calculus!

Important Note: After when this puzzle was posted, many people pointed out errors and improvements that could be made. I also noticed many flaws, so the post once had gone through drastic changes. ...
2k views

### Decipher this message for instructions to decipher this message

NINTH UNDUE COMICAL BURGER CUTLETS SLITS TURTLE REGRESS SORTS PROPHET SQUATS PUPPY ANGINA DUDS SKUNK TIGHT ODD TERSE COLONEL DIVED SOON AREA DIARIST SKUNK DREAD HASH RENTER DOWDY MAMAS GURGLE PORPOISE ...
989 views

### I need another shape 💠

Given the pattern above, which shape is next, and why?
618 views

### This clock is wrong 🕗

My clock is broken, and I can't tell what time it is. Can you help me? Hints