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The following pentagon is composed of 10 discs. Each disc must be filled with one number. The first 10 even positive numbers are allowed. The sum of the numbers to be placed in each side of the pentagon must be the same and the maximum possible. Find the sum of the numbers adjacent to the discs filled with the numbers ...
I think I can do it in one: "Will you answer "yes" to this question?" If the knave will not, he would say "no", but he has to lie and say "yes". If he will, then he would say "yes", but has to lie and say "no". The added benefit of this question is that it does not force knights into a contradictory loop (they...
<sub>This is based on the [What is a Word/Phrase™][1] series of [Phrase™][3] and [Word™][4] puzzles, started by [JLee][2].</sub> ___ If a word satisfies a certain property, it is called an Atom Splitting Word™. Use the example word lists below to find the rule. Each word can be tested for whether it is an Atom Spli...
This puzzle is in the spirit of the [What is a Word/Phrase™][1] series started by [JLee][2] with a special brand of [Phrase™][3] and [Word™][4] puzzles. If a word is satisfied by a following rule, I call it a Row word. Here is the list of Row words™ and Non-row words™: | Row Words™ | Non-Row Words™ | |:----: ...
What is a Row Word™?
You are given an L-shaped tromino, shown below. Can you surround it by 10 more L-shaped trominoes? The new trominoes can be rotated and must touch the original tromino at an edge or a corner. [![enter image description here][2]][2] This puzzle comes from the great game [Good Fences][1]. [1]: https://play.g...
Recently I was messing around with a singular knight on a chess board, and I came up with an interesting dilemma. **Can you move a knight, from starting on any square, such that it's path covers every square exactly once?** Below is the best pathing I could get, but it misses out three of the squares. [![61-Sq...
Recently I was messing around with a singular knight on a chess board, and I came up with an interesting dilemma. **Can you move a knight, from starting on any square, such that it's path covers every square exactly once?** Below is the best pathing I could get, but it misses out three of the squares. [![61-Sq...
I recently went to a furniture store where people spend my annual salary on a garish commodes and ostentatious vitrines. I noticed a curious code at the bottom of each item’s description label. Something like > CP: AUEUC each > > SP: FCOSR each > CP: MOES > > SP: VUOXS > CP: MLOES > > SP: JCSQR >...
<sub>This is based on the [What is a Word/Phrase™][1] series of [Phrase™][3] and [Word™][4] puzzles, started by [JLee][2].</sub> ___ If a word satisfies a certain property, it is called an Lefthide Word™. Use the example word lists below to find the rule. Each word can be tested for whether it is an Lefthide Word™ ...
Is it possible to interchange the positions of the the two black knights and two black rooks with those of the two white knights and two white rooks? Movements allowed are those of the corresponding pieces in the game of chess within the portion of the board available. White and black moves need not alternate. If so...
Two players alternately name dates. The winner is the player who names 31st December, and the starting date is 1st January. If a player names Xst of Y Month, the other player can name the first of the next month (1st of Month Y+1) or the next day of the current month (X+1 of Month Y). (For example, the first player beg...
What's the word I'm thinking of? * You put it in your mouth to use it, but you can't eat it or taste it. * People often point when they use it, but you can't see it or touch it. * Everyone knows how to use it, but you only use it when you don't know what it is.
Slightly stretchy but I think the answer is >! The word "what" You put it in your mouth to use it, but you can't eat it or taste it. >! You voice the word "what" to use it but the word has no specific taste. People often point when they use it, but you can't see it or touch it. >! If they are about to say "Wha...
I think the answer is >! The word "what" You put it in your mouth to use it, but you can't eat it or taste it. >! You voice the word "what" to use it but the word has no specific taste. People often point when they use it, but you can't see it or touch it. >! If they are about to say "What is that?", for examp...
What is a Fun Puzzle? <sub>I was curious to learn what makes a puzzle Fun so that I could devote my time to only working on Fun Puzzles. With that goal in mind, I set out to make a list of Fun and Not Fun puzzles. I knew this would be a contentious topic with many opinions, so I took an informal poll and below are t...
What's the word I'm thinking of? *Clue 1:* >! You put it in your mouth to use it, but you can't eat it or taste it. *Clue 2:* >! People often point when they use it, but you can't see it or touch it. *Clue 3:* >! Everyone knows how to use it, but you only use it when you don't know what it is.
I recently went to a furniture store where people spend my annual salary on a garish commodes and ostentatious vitrines. I note a curious code at the bottom of each item’s description label. Some examples: > CP: AUEUC each > > SP: FCOSR each > CP: MOES > > SP: VUOXS > CP: MLOES > > SP: JCSQR > ...
I recently went to a furniture store where people spend my annual salary on a garish commodes and ostentatious vitrines. I note a curious code at the bottom of each item’s description label. Some examples: > CP: AUEUC each > > SP: FCOSR each > CP: MOES > > SP: VUOXS > CP: MLOES > > SP: JCSQR > ...
Given the list of numbers: `(1,1), (2,2), (3,3), (4,4), (5,5), (1,4), (2,4), (1,2), (3,1), (5,1), (3,5)` `1` and `2` make `4` laugh, but only `5` makes `1` laugh. What's the rule? _________ I've been staring at this forever. I just can't figure it out. I'm given no further context.
What's the rule?
Given the list of ordered pairs: `(1,1), (2,2), (3,3), (4,4), (5,5), (1,4), (2,4), (1,2), (3,1), (5,1), (3,5)` `1` and `2` make `4` laugh, but only `5` makes `1` laugh. What's the rule? _________ I've been staring at this forever. I just can't figure it out. I'm given no further context.
What's the word I'm thinking of? *Clue 1:* > You put it in your mouth to use it, but you can't eat it or taste it. *Clue 2:* > People often point when they use it, but you can't see it or touch it. *Clue 3:* > Everyone knows how to use it, but you only use it when you don't know what it is.
Given the list of ordered pairs: > (1,1), (2,2), (3,3), (4,4), (5,5), (1,4), (2,4), (1,2), (3,1), (5,1), (3,5) 1 and 2 make 4 laugh, but only 5 makes 1 laugh. What's the rule? _________ I've been staring at this forever. I just can't figure it out. I'm given no further context.
Recently I was messing around with a singular knight on a chess board, and I came up with an interesting dilemma. **Can you move a knight, from starting on any square, such that its path covers every square exactly once?** Below is the best pathing I could get, but it misses out three of the squares. [![61-Squ...
Can you swap black and white knights in this 4x4 grid? There is one important constraint: at no point can a knight be under attack by an opponent knight. Knights move using standard chess moves (L shapes) and can be moved in any order (no need to alternate colours). [![enter image description here][1]][1] [1]...
Suppose that you take a pen and mark five points on a ball. I claim that no matter where you draw those points, I can always slice the ball into two equal halves (two equal and closed hemispheres) such that one of the halves contain exactly four of those points. Is my claim true? Source: [this Mathematics Educat...
Suppose that you take a pen and mark five points on a ball. I claim that no matter where you draw those points, I can always slice the ball into two equal halves (two equal and closed hemispheres) such that one of the halves contain exactly four of those points. Is my claim true? Source: [this Mathematics Educat...
You are given an equilateral triangle. What is the most number of such identical triangles you can place such that they do not overlap, but each one touches the original triangle?
Can you swap black and white knights in this 4x4 grid? There is one important constraint: at no point can a knight be under attack by an opponent knight. Knights move using standard chess moves (L shapes) and can be moved in any order (no need to alternate colours). Knights cannot exit the grid. [![enter image descr...
A trivial solution? >! 12 triangles: >! [![enter image description here][1]][1] [1]: https://i.stack.imgur.com/0caUE.png
Suppose that you take a pen and mark five points on a ball. I claim that no matter where you draw those points, I can always slice the ball into two equal halves (two equal and closed hemispheres) such that one of the halves contain exactly four of those points. Is my claim true? Source: [this Mathematics Educat...
A,B and C are in a three way duel. Starting with A, they rotate in the order of A-B-C, each firing one shot at a time. They stand close to one another, so that each can kill one of the others or deliberately miss. They can also adopt probabilistic strategy, like shooting at an opponent with a certain miss probability, ...
My son got this from a friend: [![enter image description here][1]][1] [![enter image description here][2]][2] It seems to be some kind of 3x3x1 Rubik's cube. I am confused about the colours, however. It can be solved for the coloured rings, but not for the dots - I think. Does anyone know the name of it s...
What is this 3x3x1 Rubik's cube with strange colours?
My son got this from a friend: [![enter image description here][1]][1] [![enter image description here][2]][2] It seems to be some kind of 3x3x1 Rubik's cube. I am confused about the colours, however. It can be solved for the coloured rings, but not for the dots - I think. Does anyone know the name of it s...
What is this 3x3x1 Rubik's cube with colored circles with colored borders?
A, B and C are in a three way duel. Starting with A, they rotate in the order of A-B-C, each firing one shot at a time. They stand close to one another, so that each can kill one of the others or deliberately miss. They can also adopt probabilistic strategy, like shooting at an opponent with a certain miss probability,...
**Table of contents** - **Introduction** - read about where the puzzle comes from. - **The puzzle** - read the puzzle itself. - **Warming up** - read about solutions to a simpler variation of the puzzle. ---------- **Introduction** (*Edit: Improved the wording and clarified the "Introduction" section...
I often see this situation in exams and I'd like to know if there is any kind of algorithm or shortcut that I can use to solve this puzzle instead of just guessing. The problem is as follows: > A space station must be evacuated to a nearby spacecraft which offered help. Four astronauts are trapped in the space st...
*The points appear to be connected, but in the end, we should have worked under aqueous conditions.* | Substance | Temperature (K) | Pressure (kPa) | |:---------------------|:---------------:|:--------------:| | Acetylene | 173.1 | 26.6 | | Ammonia | 109.5 ...
<sup>This puzzle is based off the [What is a Word™](https://puzzling.stackexchange.com/search?tab=relevance&q=what%20is%20a%20word%E2%84%A2) and [What is a Phrase™](https://puzzling.stackexchange.com/search?tab=relevance&q=what%20is%20a%20phrase%E2%84%A2) series started by [JLee](https://puzzling.stackexchange.com/user...
I recently went to a furniture store where people spend my annual salary on a garish commodes and ostentatious vitrines. I note a curious code at the bottom of each item’s description label. Some examples: > CP: AUEUC each > > SP: FCOSR each > CP: MOES > > SP: VUOXS > CP: MLOES > > SP: JCSQR > ...
A, B and C are in a three way duel. Starting with A, they rotate in the order of A-B-C, each firing one shot at a time. They stand close to one another, so that each can kill one of the others or deliberately miss. They can also adopt probabilistic strategy, like shooting at an opponent with a certain miss probability,...
please, anyone I'm trying one day and I can't go any further. this sudoku really got me. what would be the next move? Link to this sudoku [https://f-puzzles.com/?id=yzh8jxnv][1] [![enter image description here][2]][2] [1]: https://f-puzzles.com/?id=yzh8jxnv [2]: https://i.stack.imgur.com/DpIcp.p...
What would be the next move? [Link to this sudoku][1] [![enter image description here][2]][2] [1]: https://f-puzzles.com/?id=yzh8jxnv [2]: https://i.stack.imgur.com/DpIcp.png
Can you identfy the song lyric hinted at here? Read from left to right, from the top. [![enter image description here][1]][1] [1]: https://i.stack.imgur.com/clBVA.jpg
A, B and C are in a three way duel. Starting with A, they rotate in the order of A-B-C, each firing one shot at a time. They stand close to one another, so that each can kill one of the others or deliberately miss. They can also adopt probabilistic strategy, like shooting at an opponent with a certain miss probability,...
Consider the following pattern made of regular pentagons: If the pattern continued, will it form a complete loop or will the pentagons overlap? [![enter image description here][1]][1] [1]: https://i.stack.imgur.com/ni2F7.jpg
Suppose that you take a pen and mark five points on a ball. I claim that no matter where you draw those points, I can always slice the ball into two equal halves (two equal and closed hemispheres) such that one of the halves contain exactly four of those points. Is my claim true? Source: [this Mathematics Educat...
Here's my best attempt. I have no proof for this, and while the solving path seems semi-plausible, the end result doesn't really. If the result is useless, I hope the ideas I had can at least help. At some point, with the assumptions I made, I just saw it as an interesting puzzle on its own (even if my assumptions are ...
I have seen this one a few times in videogames and elsewhere, but I don't remember where. You have to open one door that has several locks on it. You have a bunch of levers that when moved change the state of some of the locks (open/closed), but the catch is that some levers control the same locks and when you thin...
What's that videogame puzzle where several levers change the locks state on one door?
I have seen this one a few times in videogames and elsewhere, but I don't remember where. You have to open one door that has several locks on it. You have a bunch of levers that when moved change the state of some of the locks (open/closed), but the catch is that some levers control the same locks and when you think...
What's that videogame puzzle where several levers change the locks' state on one door?
<sup>An entry in [Fortnightly Topic Challenge #50: Escape Rooms](https://puzzling.meta.stackexchange.com/questions/7172/)</sup> --- Your head is throbbing like mad. You try to get your bearings as you look around the laboratory. Shattered beakers and spilled chemicals are everywhere. Another failed experiment. Ho...
[Source:][1] > I like orange and at the same time I hate orange, how is this possible? I rephrased the puzzle from [Gpuzzles][1] to prevent searching. So don't waste your time. [1]: https://gpuzzles.com/?source=external&stack=1
Mr. Blue lives in the blue house, Mr. Pink lives in the pink house, and Mr. Brown lives in the brown house. Who lives in the white house? *I don't know why, but I'm obsessed with easy riddles.*
Easy Riddles #1 - Who lives in the white house?
This is probably the simplest paradox out there and it still confuses me, here it is. The sentence below is true. The sentence above is false. I've known about this one for a few years and it has troubled me ever since. Can someone try and find a solution so I can finally rest?
Suppose that you take a pen and mark five points on a ball. I claim that no matter where you draw those points, I can always slice the ball into two equal halves (two equal and closed hemispheres) such that one of the halves contain exactly four of those points. Is my claim true? Source: [this Mathematics Educat...
Suppose that you take a pen and mark five points on a ball. I claim that no matter where you draw those points, I can always slice the ball into two equal halves (two equal and closed hemispheres) such that one of the halves contain exactly four of those points. Is my claim true? Source: [this Mathematics Educat...
What's that puzzle where several levers change the locks' state on one door? (Edit: Lights Out)
What's that puzzle where several levers change the locks' state on one door?
A, B and C are in a three way duel. Starting with A, they rotate in the order of A-B-C, each firing one shot at a time. They stand close to one another, so that each can kill one of the others or deliberately miss. They can also adopt probabilistic strategy, like shooting at an opponent with a certain miss probability,...
Let's have the following sequence 43, 108, 5737, 13932, 97613377, 239783652,? What number belongs where the the question mark is?
Let's have the following sequence 43, 108, 5737, 13932, 97613377, 239783652,? What number belongs where the question mark is?
You wake up in a room (again) that has two floors, Both have 3 puzzles. In order to escape, You have to find every answer in this order: Red Yellow Green Cyan Navy Pink and combine it together (eg if 75 is Red then 64 is Yellow then the answer is 7564) Most of them are patterns, so get ready! First Floor ======= ...
4 player answer (Note: I removed by earlier wrong 3 person answer) The best thing D can do is say: >! If and only if C gives me a nonzero chance of survival, C will inherit my gun. Why? >! C can dictate the chances of survival exactly (assuming D does not doom their self), as long as he gives A and B a nonzero...
A, B and C are in a three way duel. Starting with A, they rotate in the order of A-B-C, each firing one shot at a time. They stand close to one another, so that each can kill one of the others or deliberately miss. They can also adopt probabilistic strategy, like shooting at an opponent with a certain miss probability,...
What's that puzzle where multiple levers change the locks' states on one door?
[![enter image description here][1]][1] **Across** 3\. High-pitched sound of loud automobile coming around too regularly (8) 7. Old TV show prosecutor's entertaining everyone (6) 9. Town in Arcadia orders one to retire (6) 10. Shake alien's spaceships (7) 11. Plan of wrestler and actor, John: Visiting...
[![enter image description here][1]][1] **Across** 3\. High-pitched sound of loud automobile coming around too regularly (8) 7. Old TV show prosecutor's entertaining everyone (6) 9. Town in Arcadia orders one to retire (6) 10. Shake alien's spaceships (7) 11. Plan of wrestler and actor, John: Visiting...
4 player answer EDIT: I strongly believe my answer is wrong. So (find the flaw and) post a better answer before I update. :-) The best thing D can do is say: >! If and only if C gives me a nonzero chance of survival, C will inherit my gun. Why? >! C can dictate the chances of survival exactly (assuming D...
I got all but one...completed grid coming shortly. **ACROSS** >! 3. FALSETTO = F (forte/loud) + TESLA< + ToO >! 7. DALLAS = DA'S + ALL >! 9. ASTROS = A + SORTS< >! 10. ROCKETS = ROCK + ET'S >! 11. SCENARIO = S (small) + CENA + RIO >! 12. TOE IN = TO + EIN >! 14. XI'AN = X (cross) + IAN >! 15....
I got all but one...completed grid coming shortly. **ACROSS** >! 3. FALSETTO = F (forte/loud) + TESLA< + ToO >! 7. DALLAS = DA'S + ALL >! 9. ASTROS = A + SORTS< >! 10. ROCKETS = ROCK + ET'S >! 11. SCENARIO = S (small) + CENA + RIO >! 12. TOE IN = TO + EIN >! 14. XI'AN = X (cross) + IAN >! 15....
4 player answer The best thing D can do is say: >! If and only if C gives me a nonzero chance of survival, C will inherit my gun. Why? >! C can dictate the chances of survival exactly (assuming D does not doom their self), as long as he gives A and B a nonzero chance. It does not matter to Cs survival how he ...
here is a new quiz from my daily quiz calendar. I'm trying to find a way to solve it. [![enter image description here][1]][1] [1]: https://i.stack.imgur.com/uFmkl.png The numbers 1-6 should be filled in. And like a sudoku each row and each column should contain each number exactly one time. Moreover the c...
Grid: >! [![enter image description here][1]][1] **Across** >! 3. FALSETTO **F TESLA< T(-o)O** High-pitched sound of loud automobile coming around too regularly (8) >! 7. DALLAS **DA'S entertaining ALL** Old TV show prosecutor's entertaining everyone (6) >! 9. ASTROS **(SORTS A)<** Town in Arcadia orders...
**COMPLETED GRID** >! [![Completed grid][1]][1] **ACROSS** >! 3. FALSETTO = F (forte/loud) + TESLA< + ToO >! 7. DALLAS = DA'S + ALL >! 9. [ASTROS][2] = A + SORTS< >! 10. ROCKETS = ROCK + ET'S >! 11. SCENARIO = S (small) + CENA + RIO >! 12. [TOE IN][3] = TO + EIN >! 14. [XI'AN][4] = X (cross) + IA...
here is a new quiz from my daily quiz calendar. I'm trying to find a way to solve it. [![enter image description here][1]][1] The numbers 1-6 should be filled in. And like a sudoku each row and each column should contain each number exactly one time. Moreover the colored fields are used for calculation. For ...
Here is a new quiz from my daily quiz calendar. I'm trying to find a way to solve it. [![enter image description here][1]][1] The numbers 1-6 should be filled in. And like a sudoku, each row and each column should contain each number exactly one time. Moreover the colored fields are used for calculation. For...
I have a simple grid puzzle: Example: ``` | X | Y | X | | Y | X | Y | | Y | X | Y | ``` The move is defined as a row or a column move. So when you move one cell, whole column/row moves. Example **top row right 2 steps**: ``` 1 step | X | X | Y | | Y | X | Y | | Y | X | Y | 2 step | Y | X ...
Use this tag when a puzzle provides some information about a situation, and requires working through clues to arrive at an answer. Clues might be snippets of conversation, transcripts of letters, pictures of a scene, etc. These puzzles will generally be dressed up as a narrative/story, and the [story] tag will usually ...
<sup>An entry in [Fortnightly Topic Challenge #52: Polyominoes](https://puzzling.meta.stackexchange.com/questions/7188).</sup> --- I had heard that my good friend [Ingrid Deduction](https://puzzling.stackexchange.com/questions/102697/) was back in town, so I popped round to her apartment today, only to find she'd g...
<sup>An entry in [Fortnightly Topic Challenge #52: Polyominoes](https://puzzling.meta.stackexchange.com/questions/7188).</sup> --- I had heard that my good friend [Ingrid Deduction](https://puzzling.stackexchange.com/questions/102697/) was back in town, so I popped round to her apartment today, only to find she'd g...
**Very Partial Answer** I think I've got the gist of what's going on so maybe if I post what I have so far, it may inspire somebody else. Firstly, >! There is a strong underlying theme of chemical elements, particular chemical symbols for the elements, being used. Post-it Note >! The first line of the first ...
<sup>An entry in [Fortnightly Topic Challenge #50: Escape Rooms](https://puzzling.meta.stackexchange.com/questions/7172/)</sup> --- Your head is throbbing like mad. You try to get your bearings as you look around the laboratory. Shattered beakers and spilled chemicals are everywhere. Another failed experiment. Ho...
I am officially an idiot. I spent several hours figuring out brilliant deductions and got really good progress with many actual numbers on the grid, and even though I got stuck at places, there was always some clever bit that got me just that much forward. In the end, I was just about to fill the grid in two dif...
Let's have the following sequence 43, 108, 5737, 13932, 97613377, 239783652,? What number belongs where the question mark is? HINT: The next number is 28693771291496497. What is the next term after that?
**COMPLETED GRID** >! [![Completed Grid][1]][1] The first step: >! Remember that Stiv *loves* the periodic table. Then have a vague idea, but be able to look up in Wikipedia, that the periodic table is 9x18, just like this puzzle. And the number of unshaded squares is 118, just like the number of elements. Now we'...
I believe the next few numbers are >! 28693771291496497 (as given in the hint), 70218276063338412, 2466867942031109947559641241498257, 519657642496019930838140921497014645213420297443652. And, just for fun, the _previous_ numbers are >! 1, 3, 4, 9. If we write >! the sequence as $a_1,b_1,a_2,b_2,\ldots$ ...
**COMPLETED GRID** >! [![Completed Grid][1]][1] The first step: >! Remember that Stiv *loves* the periodic table. Then have a vague idea, but be able to look up in Wikipedia, that the periodic table is 9x18, just like this puzzle. And the number of unshaded squares is 118, just like the number of elements. Now we'...
**COMPLETED GRID** >! [![Completed Grid][1]][1] The first step: >! Remember that Stiv *loves* the periodic table. Then have a vague idea, but be able to look up in Wikipedia, that the periodic table is 9x18, just like this puzzle. And the number of unshaded squares is 118, just like the number of elements. Now we'...
**COMPLETED GRID** >! [![Completed Grid][1]][1] The first step: >! Remember that Stiv *loves* the periodic table. Then have a vague idea, but be able to look up in Wikipedia, that the periodic table is 9x18, just like this puzzle. And the number of unshaded squares is 118, just like the number of elements. Now we'...
We have a well known peg solitaire which is not played yet as seen below: [![enter image description here][1]][1] At most how many squares can you make by joining the points as exemplified below? [![enter image description here][2]][2] Note: No ball (point) in the middle! Don't use it in your summing. ...
I'm not a terrorist, but you don't like me,  I'll mess up your code and your recipes,  I'll bring software to its knees,  You can find one like me in all industries. Who am I? Hint: >! One word, that's one you've definitely already thought of. You may be unfamiliar with it, with a suffix on i...
I believe the next few numbers are >! 28693771291496497 (as given in the hint), 70218276063338412, 2466867942031109947559641241498257, 519657642496019930838140921497014645213420297443652. And, just for fun, the _previous_ numbers are >! 1, 3, 4, 9. If we write >! the sequence as $a_1,b_1,a_2,b_2,\ldots$ ...
What 2-word associates with this rebus? (actually not a rebus) [![enter image description here][1]][1] also: What word associates with this rebus? [![enter image description here][2]][2] [1]: https://i.stack.imgur.com/KMKsl.png [2]: https://i.stack.imgur.com/tp83C.png
<sup>An entry in [Fortnightly Topic Challenge #50: Escape Rooms](https://puzzling.meta.stackexchange.com/questions/7172/)</sup> --- Your head is throbbing like mad. You try to get your bearings as you look around the laboratory. Shattered beakers and spilled chemicals are everywhere. Another failed experiment. Ho...