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].
93
questions
79
votes
15
answers
16k
views
Making π from 1 2 3 4 5 6 7 8 9 [closed]
There have been two other questions here and here that are similar to this one, but this changes the rules up a little.
Your job is to approximate $\pi$ using the sequence of digits (in order):
1 2 3 ...
- 5,023
62
votes
19
answers
10k
views
Growing anagrams - What is the longest possible list forming a sentence? [closed]
This is a challenge for word-puzzle lovers. It might be a bit more of a game than a puzzle, but I think it is not limitless in it's answers, so a final answer could be found (eventually).
What is the ...
- 18.2k
46
votes
9
answers
24k
views
The Longest Word Made from Chemical Symbols [closed]
So, as you probably know, each and every element in the Periodic Table has its own unique chemical symbol, which is either one, two, or three letters long. For instance, Oxygen is represented as O and ...
- 1,002
34
votes
21
answers
12k
views
3:3! It's a football score! [closed]
Given to me, by a friend:
How would you make 20, using two threes?
You may use any basic operation. And others, such as square roots (the symbol), factorials, etc. Any operation is allowed.
Just ...
- 551
29
votes
7
answers
16k
views
The most words that can be made by successively adding one letter to the original word? [closed]
What is the largest number of words that can be made by just adding one letter to the original word, where each iteration is a meaningful word? E.g.
...
- 401
26
votes
18
answers
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 ...
- 1,587
25
votes
13
answers
5k
views
A rhopalic sentence of at-least 5 words, beginning with as long word as possible [closed]
Rhopalic sentences are sentences which have words whose length is one more than the previous word. eg:
I do not hunt birds.
I do not know where family doctors acquired illegibly perplexing ...
- 1,297
25
votes
9
answers
3k
views
Longest "De Bruijn phrase" in English [closed]
Let's call De Bruijn n-phrase a sequence $S$ of n words $W_1 W_2 W_3... W_n$ such that any "left-rotation" of its words constitutes a correct and meaningful phrase. The left-rotations of $S$ are:
$...
- 465
23
votes
2
answers
3k
views
Open-ended challenge: Find the longest morsagram word pair [closed]
The idea for this challenge stems from this posting on ComputerScience (beta).
It is established (see above link), that Morse-code requires the 'space' between individual character to be uniquely ...
- 18.2k
22
votes
13
answers
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 ...
- 1,489
21
votes
9
answers
5k
views
Riddles/puzzles having answer hidden in the question? [closed]
Can you give any example of riddles or puzzles in which the answers are someway "cleverly hidden" inside the question?
I think that such examples are more common in word-related riddles, but maybe ...
- 2,890
21
votes
8
answers
5k
views
Craft the longest Scrabble sentence [closed]
This is another challenge along the same vein as similar challenges that have shown up on this site, requiring the puzzle to craft the longest possible sentence given a specific requirement.
What is ...
- 17k
21
votes
9
answers
2k
views
Word Tank-chain-wheel Challenge [closed]
My niece gave me this word wheels challenges the other day and I comes up with an alternative. Here's how this challenge works:
Find a word that can form another word by moving its first letter ...
- 8,576
19
votes
7
answers
3k
views
What is the longest rhymonym? [closed]
What is the longest pair of words you can find that rhyme and can also be synonyms / used to describe the same phenomenon?
For instance, spot and ...
- 17.5k
18
votes
26
answers
12k
views
Building a 2 mile runway on a 1x1 mile island [closed]
You have a 1-mile long x 1-mile wide island.
When taking off from a flat runway, a plane requires a runway of minimum length 2 ...
- 957
17
votes
18
answers
41k
views
Find words with the highest proportion of a single letter [closed]
Thanks to JoeZ, pacoverflow, isaacg, Sp3000, Novarg, Ram, h34, and all those who contributed answers that have since been beaten. I've accepted JoeZ's answer since he has the most mentions on the list ...
- 117k
16
votes
5
answers
2k
views
Second-rate spelling [closed]
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...
- 79.7k
15
votes
8
answers
7k
views
Longest Word With *Only* Repeating Character Pairs [closed]
Inspired by and Opposite of: Longest Word without repeating character-pairs
The challenge is to find an English word in which every character pair appears at least twice. ("Word" does not include ...
- 17.5k
15
votes
3
answers
1k
views
How many consecutive integers can you make using only four digits? [closed]
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,...
- 2,968
14
votes
3
answers
835
views
Forced selfmate in n-moves [closed]
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 ...
- 22.1k
13
votes
14
answers
4k
views
Shortest sentence with two auto-antonyms [closed]
You have to use two words that are each their own opposite (auto-antonyms, contronyms, contranyms or whatever you want to call it) in the same sentence. This means that each of the two words in used ...
- 14.5k
13
votes
3
answers
1k
views
From jafe to El-Guest [closed]
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 ...
- 21.7k
13
votes
6
answers
3k
views
Can you solve those laser puzzles? (puzzles created by the community) [closed]
So, I was bored and I made a small game for this site! In this game the user who solves the previous puzzle gets to create the next one and they will always be more complex. Website link and string ...
- 1,266
12
votes
10
answers
1k
views
Four fours to get $\pi$ [closed]
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 ...
user63779
11
votes
11
answers
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 ...
- 2,968
11
votes
11
answers
6k
views
Longest sentence with each letter repeated n times [closed]
Inspiration:
This question was inspired by Word sets with no repeating letters
Rules:
Sentences can be of any length.
Every letter used in this sentence, must be used n times.
n can be any number.
...
- 14.5k
11
votes
8
answers
8k
views
Longest sentence where all words are anagrams of each other [closed]
Won, now own.
Rules:
A “word” is an entry on dictionary.com.
A “sentence” is any text that is grammatically correct, has a complete meaning in the English language, starts with a capital letter and ...
- 1,925
11
votes
7
answers
3k
views
Longest arithmetic expression where the answer is equal to the number of letters [closed]
You can use any mathematical operations represented by English words. These English words must be found in a commonly used dictionary.
Spaces are neither letters nor words.
You can not use the same ...
- 14.5k
11
votes
5
answers
1k
views
Knight on the keyboard [closed]
You are given a QWERTY keyboard, and are allowed to choose where you wish to start. You are only able type in the same way a knight is able to move on a chessboard (but in this case, on the keyboard). ...
- 5,868
11
votes
1
answer
534
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 ...
- 259
11
votes
1
answer
573
views
Bouncing Robots: Graphical Puzzle [closed]
Robots are indicated by the arrowhead shapes and the labels "r", "y", "b", "g". The label obviously corresponds to their color. The aim of the puzzle is to pick up the shapes and put them down in the ...
- 113
8
votes
12
answers
3k
views
One syllable words with many vowel sounds [closed]
I'm not entirely sure how to word this, but what is the largest set of one syllable words you can find in which every phonetic sound is the same except the vowel? For example, 'arc', 'orc', and 'irk' ...
- 3,662
8
votes
3
answers
1k
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 ...
- 18.2k
8
votes
4
answers
682
views
The Longest Word Made from Specific Chemical Symbols [closed]
So, my first question on this topic was answered fairly quickly with quite a long word, so I thought I might post a different version of the puzzle
The idea this time is similar to last time: you ...
- 1,002
7
votes
3
answers
765
views
What is the Sparsest Word? [closed]
Side note: If you know a better way to describe an anagram that doesn't use all the letters except for "words within the word" or some other lengthy phrase, please let me know. I considered asking ...
- 17.5k
7
votes
5
answers
700
views
Transatlantic road paint [closed]
In the US, text painted on roads reads bottom to top:
AHEAD
STOP
In the UK, it reads like normal text:
NO
ENTRY
...
- 1,057
7
votes
5
answers
943
views
Highest possible score my friend could earn in one Scrabble turn? [closed]
My friend has a great vocabulary but is also quote humble.
Every time we play Scrabble he wins easily. He says he tries his best, with one exception:
If the opportunity ever arose, he would never ...
- 468
7
votes
3
answers
614
views
Magic-the-Gathering Challenge: Cheapest Legacy Turn 1 kill [closed]
Your Goal: Win the game turn 1 with you beginning the game (so not on the draw) using the cheapest price total of cards used.
Rules:
Use the "Price Trend" price from http://www.magiccardmarket.eu ...
- 11.5k
7
votes
1
answer
455
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'...
- 22.1k
7
votes
2
answers
600
views
MathJax: ones and zeros
Do or do not, there is no try. — Yoda
Here is another MathJax puzzle. The Starring MathJax puzzle involved handling numbers in MathJax, even though there are no count registers or ...
- 678
7
votes
1
answer
358
views
She Lia Squared: Our daughter asked, “How many words can it make?”
Our daughter recently conned my wife and I into purchasing interlocking foam squares for her bedroom floor. On each square is a different letter of the alphabet. To cover her entire floor we had to ...
- 87
7
votes
3
answers
918
views
Starring MathJax
Twinkle, Twinkle, little star...
Having enjoyed @Humn's recent MathJax puzzles (MathJax exposed and MathJax re-flex), I decided to contribute some of my own.
This one is a classic $\rm\TeX$ exercise,...
- 678
6
votes
7
answers
4k
views
Find the longest string of words such that the (4 letter) end of one word is the start of the next [closed]
Here is an open-ended challenge.
Find the longest series of English words such that the final four letters of word $n$ are the same as the first four letters of word $n+1$.
Example
(3 words) ...
- 8,117
6
votes
6
answers
2k
views
Challenge: Longest x-height word/sentence [closed]
A common puzzle is to see how to make sentences from the same letters, or the longest word in alphabetical order, etc. see here for a list.
Now 'the x-height or corpus size refers to the distance ...
- 2,662
6
votes
4
answers
490
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 ...
- 471
5
votes
7
answers
1k
views
What is the smallest positive number on an 8-segment array? (no repeats) [closed]
You are provided with the 8-segment array in the picture together with all the necessary electronics to make any combination of lit segments you want.
Fillable version for graphics. https://i.sstatic....
- 8,117
5
votes
8
answers
3k
views
Longest Word without repeating character-pairs [closed]
What's the longest English word that doesn't contain the same two letters in a row more than once?
Good word : too contains to ...
- 4,273
5
votes
4
answers
817
views
Challenge : Create a star shaped crosswords (Smaller numbers of distinct letters wins !) [closed]
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 ...
- 17.9k
5
votes
2
answers
248
views
Anagrammatical substrings [closed]
Inspired by this challenge, I have a similar, with stricter rules.
Find a word that can be decomposed into several other words (more than one). Those words are not allowed to be proper substrings of ...
- 5,148
5
votes
3
answers
1k
views
English word with most valid substrings [closed]
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, ...
- 53