Questions tagged [open-ended]

OPEN-ENDED PUZZLES ARE NO LONGER IN SCOPE. Used when no answer can be guaranteed to be the last, best one. If a puzzle instead has a provably optimal solution, tag with [optimization].

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2
votes
2answers
452 views

Longest “Cycle” word chain [closed]

Linked to This word chain will come back to me. That puzzle got some very creative answers and comments. Although the puzzle itself took some work, I found it very interesting. So here is a more ...
11
votes
10answers
847 views

Four fours to get $\pi$

Four fours is a famous puzzle (made trivial with logarithms). For this puzzle, we take inspiration from Glen O's challenge from a few years back. The rules here are slightly different, but the goal is ...
2
votes
3answers
175 views

Google Searches With no Results [closed]

What is the shortest string of letters that yields no results in a Google search? When answering, please use the NATO alphabet in order to prevent the string from becoming a search result. Scoring: ...
8
votes
10answers
6k views

There are polygons with only right angles which have an odd number of corners

One of the interesting myths about a certain building in our university is that it has 13 corners. One way to dismiss this claim is to point out that a polygon with right angles must have an even ...
1
vote
1answer
226 views

A sentence with all numbers [closed]

Crazy thought. Can you make an (grammatically correct) english sentence using english words which are all numbers? Each word in that sentence must represent a number. I am expecting a minimum 6 ...
-1
votes
1answer
132 views

What is the Longest Meaningful Sentence U can make Using single letters only? [closed]

Some Examples: I C U. S I M A B.
14
votes
6answers
1k views

Pulling Apart a Jigsaw Puzzle

Assume you have a jigsaw puzzle that is also a tessellation. This means every piece has an identical shape and can be assembled into a 2D pattern that fills the plane with no gaps. Such a jigsaw ...
3
votes
2answers
929 views

Dreadful Dastardly Diseases, or Always Atrocious Ailments [closed]

So the other day, I was in a pharmacy and I saw that they had a "cold 'n' cough" medicine. The alliteration caught my eye, and I wondered it would be possible to create alliterative names with other ...
14
votes
3answers
1k views

From jafe to El-Guest

Largely inspired by From Puzzling to StackExchange by CodeNewbie From jafe to El-Guest jafe > cafe > cate > cete > cet > get > gest > egest > e gest > e guest > el guest Rules: In any move, you ...
12
votes
3answers
770 views

Masyu puzzles with many circles

The rules of Masyu: Make a single loop with lines passing through the centers of cells, horizontally or vertically. The loop never crosses itself, branches off, or goes through the same cell twice. ...
17
votes
5answers
2k views

Second-rate spelling

Find the longest word which can be spelled with the second letters of a group words in alphabetical order. An example with incomprehensible (16 letters): a...
7
votes
5answers
360 views

Breaking Balance (Part A)

If we assume the classic balance puzzle (Twelve balls and a scale) is phrased like this: You have 12 coins that are identical except for one counterfeit that is heavier or lighter. Can you use a ...
20
votes
1answer
876 views

Peaceful Encampments

This math puzzle is due to Donald Knuth (as far as I know; maybe he got it from someone else) circa 2014. Consider a plain represented by the unit square. On this plain we want to “peacefully ...
4
votes
1answer
154 views

What's the most triangles you can make with 4, 5 or 6 straight lines?

All the triangles can stick together. The triangles counted is the independent triangles, triangles made up of two shapes, a triangle made up from 3 shapes, or the outline of the shape consisting of 4,...
3
votes
3answers
1k views

Three coins for the fair king [duplicate]

Based on the question Eight coins for the fair king: I saw a comment saying "There isn't a good solution known even with three coins in all cases". So the challenge here is to try to solve ...
2
votes
2answers
168 views

Heaven or Hell? [closed]

To decide whether you go to heaven or hell, your life is put on the balance. All depends on which way it tips. John dies and waits in line to have his life weighed. Eventually he reaches St Peter who ...
3
votes
1answer
136 views

A construction toy for children [closed]

Alice has an idea for a construction toy made from plastic. Each building block is in the shape of an uppercase letter of the alphabet. No other characters are to be used. Children will ...
1
vote
1answer
186 views

Wicked Winding Words!

What is the highest number $n$ of $n$-letter words can you find that share this property? i.e. highest number $n$ that you can find (not found on any other sites). I will accept the answer with the ...
5
votes
1answer
719 views

What is the longest word that can be made out of all the scrabble tiles?

What is the longest word that can be made out of all the Scrabble tiles? If you didn’t know, there are 100 tiles when you play Scrabble. I was wondering what was the longest word you could make out ...
6
votes
3answers
330 views

Moans to Rocky in 4 moves?

In his novel A Case of Need, one of Michael Crichton's characters claims that the classic word‑ladder‡ "MOANS to ROCKY" can be made in 4 moves (5 lines total). But the book does not ...
19
votes
4answers
3k views

A Tic-Tac-Toe type game

I found this interesting game with no name: You have a 1x11 grid, like this. The way you play is similar to Tic-Tac-Toe (aka Noughts and Crosses). Players take turns to place Xs and Os on the grid, ...
3
votes
3answers
744 views

Make a sentence with the most different uses of the same word [closed]

Background I recently stumbled across the following grammatically correct sentence: Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo. This sentence relies on the fact that the ...
3
votes
2answers
281 views

Longest autological loop? [closed]

A word is said to be autological if it describes itself. This can be a property of both nouns and adjectives; for example, "noun" is a noun and "pentasyllabic" is pentasyllabic. We can also construct ...
3
votes
3answers
369 views

Make me a room-filling pattern! [closed]

So I need a new knitting pattern, but I figured this might be a nice puzzle. I'm looking for a pixelated 2D-shape that can be used in a room-filling pattern (rotation and flipping allowed). The ...
8
votes
2answers
748 views

Improve my 3D puzzle

3D View of one solutions http://autode.sk/2Dg4FWx I designed a 4x4x4 soma cube in AutoCad and then built it with wood cubes. There are twelve pentacubes and one tetracube. Each piece is unique and if ...
10
votes
2answers
325 views

Create a 1 meter measure

How many folding steps do you need to create a $1 \, \text{m}$ measure from an ideal DIN A0 sheet? This sounds easy, but consider that this paper has edge lengths of $\sqrt[4]{2} \, \text{m}$ and $\...
10
votes
1answer
477 views

Conway's Siege of Life

They are immortal and they are killing us. We may not be able to kill them, but we might be able to keep them occupied, distracted, for eternity. But we need to figure out how. Before there are no ...
26
votes
18answers
16k views

Don't settle for a billion [duplicate]

While Artur is willing to settle for a billion, I'd like a much bigger return on my two matchstick investment. Moving only two matchsticks, what is the largest number that can be created from the ...
5
votes
3answers
870 views

English word with most valid substrings

What English word has the most valid word substrings, no repeats? Examples (I may have missed some words): AIRSPACES: a, i, air, spa, space, spaces, pace, paces, ace, aces DEMONETIZED: demo, demon, ...
10
votes
11answers
12k views

Infinitely long loaf of Bread [closed]

You are visiting your old friend Mike at Infinitely's Baking Shop. Just as you arrived, he was taking out a fresh, infinitely long loaf of bread. Both of its ends extend infinitely long in a ...
6
votes
4answers
449 views

Constructing 0.35 Unit Length

The Problem The medieval equivalent of Bob the Builder has a new job offer: He is to build a box with the measures of $0.35$ units by $0.35$ units by $0.35$ units for a king. There is a little ...
6
votes
1answer
442 views

Picture a graph without words

You may have played/sung/heard a song without words in concert, in choir, and in a Sushi restaurant. Who hasn’t?! Well here is a picture without words, only axes: And here it is without JPG-...
5
votes
3answers
457 views

Find the most MissSpellable word, but in a good way?

Most MissSpellable Word - English? I'm not a native English speaker but I tend to keep an eye on my spelling and grammar. I recently misspelled "throw" as "throe", which, to my surprise, was a real ...
15
votes
3answers
1k views

How many consecutive integers can you make using only four digits?

In the spirit of the classic four fours, I wonder what's the optimal set of four numbers? Your goal is to make the most consecutive integers using four digits of your choice. Pick four: $0,1,2,3,...
5
votes
4answers
780 views

Challenge : Create a star shaped crosswords (Smaller numbers of distinct letters wins !)

Rules: Create a star-shaped crossword using 6 letters English words. Clues for the crossword is not needed. Use common English words. Direction for diagonals is TOP to DOWN. Direction for Horizontal ...
22
votes
13answers
7k views

Playing “Guess a Number” with myself

I want to play a game where one person thinks of a number and the other tries to guess it, but I want to play this game by myself. The puzzle is to come up with a way to play this game. Rules (have ...
14
votes
3answers
765 views

Forced selfmate in n-moves

I assume most people on PSE know a bit of chess With white to move, this is checkmate (1. Qb7#): That's boring. Let's try something more interesting. With black to move, black can FORCE white to ...
-6
votes
1answer
273 views

Any twelve year-old can answer this question [closed]

Come up with a question between five and ten words long with an answer that contains more than three times as many unique words as the question, does not contain any of the question words, and does ...
4
votes
1answer
487 views

Infinitely simple polygon solipsism

           Solipsism — The self is all that can be known to exist. Above is a simple polygonal region divided into infinitely many different-...
9
votes
3answers
385 views

Unreflected infinitely simple polygon reflexivity

(This was retrofitted to more tightly match a surprise solution and to allow for another puzzle with the original intent.)                   &...
10
votes
4answers
776 views

Prime Circuit Optimisation

It's logic gates time! You are only allowed to use NOT, OR, AND, XOR gates, accepting 1,2,2,2 inputs respectively. PART ONE You must build a circuit with $n$ inputs, and 1 output. The output must be ...
6
votes
1answer
259 views

She Lia Squared: Our daughter asked, “How many words can it make?”

For puzzle experts out there I'm certain this will seem trivial. Our daughter recently conned my wife and I into purchasing interlocking foam squares for her bedroom floor. On each square is a ...
7
votes
1answer
436 views

Character Navigation

Consider the following grid of streets with roadblocks: If you are facing in the direction of the arrow and want to get to the dot, the highlighted path is the shortest: This traces out an L. Let'...
4
votes
1answer
246 views

The Autonumerigram Challenge [duplicate]

Some phrases both refer to a number, n, and are comprised of n alphabetic characters. I call any such phrase an autonumerigram. For example, four has 4 letters seven plus seven has 14 letters ...
12
votes
2answers
548 views

KenKen Zen: A journey begins

Let us shy away from the materialistic opulence of 361- cell KenKen layouts (−9 to +9, squared).  Let us contemplate a modest KenKen journey, unburdened by gratuitously ...
8
votes
3answers
697 views

Building the ideal Scrabble dice set

This is a genuine question and I don't know the "correct" answer to this. I'm also of two minds if it is really on-topic on the site. Finding the answer is surely "a puzzle" (if ...
6
votes
1answer
311 views

A Stranger (Chess Sliding Puzzle)

A suspicious stranger lurks in the village. Deal with him before escorting the King to the luxurious safety of h8. White is first to move. Only legal chess moves are allowed. Pawns are not promoted ...
14
votes
3answers
417 views

Pool of Pawns (Chess Sliding Puzzle)

The King has tired of watching the Queen swim in the Pool of Pawns. Help him return to his palace on h8 using as few moves as possible. Only legal chess moves are allowed. Pawns are not promoted on ...
30
votes
3answers
1k views

Rook River (Chess Sliding Puzzle)

The absent-minded king has gotten himself lost. Help him return to his palace on h8 using as few moves as possible. Only legal chess moves are allowed. Pawns are not promoted on the final rank. You ...
5
votes
1answer
293 views

Can You Find a Tower of Hanoi Word?

Consider a simple Tower of Hanoi set consisting of three rods and three disks. This tower has an optimal solution of seven moves; these seven moves are the only ones allowed in what follows. For the ...