Island of LiarsKill the jokers! - Part 1Kill the jokers! - Part 2Another village of liars and truth-tellersLiar and the Truth teller with 6 inhabitantsThree truth teller boys on an islandWho led the mutiny?What did he say he said? Liars with a twist!How many liars are in the room?Liar liar pants on fireRound tabel conference with liars?

Why is Collection not simply treated as Collection<?>

How much of data wrangling is a data scientist's job?

What's the point of deactivating Num Lock on login screens?

I Accidentally Deleted a Stock Terminal Theme

Is it legal for company to use my work email to pretend I still work there?

Why are electrically insulating heatsinks so rare? Is it just cost?

Blender 2.8 I can't see vertices, edges or faces in edit mode

Has there ever been an airliner design involving reducing generator load by installing solar panels?

Why doesn't H₄O²⁺ exist?

Can one be a co-translator of a book, if he does not know the language that the book is translated into?

Is it possible to create light that imparts a greater proportion of its energy as momentum rather than heat?

Where does SFDX store details about scratch orgs?

Western buddy movie with a supernatural twist where a woman turns into an eagle at the end

Why does ы have a soft sign in it?

Were any external disk drives stacked vertically?

How do I find out when a node was added to an availability group?

How can I tell someone that I want to be his or her friend?

Why do I get two different answers for this counting problem?

Why can't we play rap on piano?

Infinite Abelian subgroup of infinite non Abelian group example

Issue with type force PATH search

Emailing HOD to enhance faculty application

Brothers & sisters

Why does Optional.map make this assignment work?



Island of Liars


Kill the jokers! - Part 1Kill the jokers! - Part 2Another village of liars and truth-tellersLiar and the Truth teller with 6 inhabitantsThree truth teller boys on an islandWho led the mutiny?What did he say he said? Liars with a twist!How many liars are in the room?Liar liar pants on fireRound tabel conference with liars?













10












$begingroup$


A king goes to an island, where there are 5823 people who always tell the truth and 8723 who always lie.



The king is special guest for the party celebrating 2053 year.



On the party, liars and truth tellers dance in couples (everyone can dance with everyone), some people leave the dance, others join and some don't even participate in the dances as they are not dance lovers.



After the party, the king asked everyone who had danced on the party, how many truth tellers did he dance with and put the numbers into his diary.
Surprisingly, when he checked his diary later on, he found out he had all the numbers from 0 to 956 typed in uniquely.




How many truth tellers danced on the party, assuming everyone knows who is truth teller and who is liar?











share|improve this question











$endgroup$







  • 3




    $begingroup$
    Just to clarify a few things: 1. Do the liars have to put down a specific number, or can they just write down any number at all as long as it’s not the number of people they danced with? 2. Does the king participate in the dancing? Thanks!
    $endgroup$
    – PiIsNot3
    Mar 27 at 9:37






  • 1




    $begingroup$
    1. Everyone can type whatever he/she wants as long as it's truth or lie. 2. Doesn't matter if king danced at all.
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 9:47











  • $begingroup$
    Is the King lying? What does a truth-teller say about dancing with the King?
    $endgroup$
    – Weather Vane
    Mar 27 at 9:52











  • $begingroup$
    Got the right answer, but even if the king was liar/truth teller it would still fit in, but no he didn't dance at all, he dislikes dancing.
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 9:57















10












$begingroup$


A king goes to an island, where there are 5823 people who always tell the truth and 8723 who always lie.



The king is special guest for the party celebrating 2053 year.



On the party, liars and truth tellers dance in couples (everyone can dance with everyone), some people leave the dance, others join and some don't even participate in the dances as they are not dance lovers.



After the party, the king asked everyone who had danced on the party, how many truth tellers did he dance with and put the numbers into his diary.
Surprisingly, when he checked his diary later on, he found out he had all the numbers from 0 to 956 typed in uniquely.




How many truth tellers danced on the party, assuming everyone knows who is truth teller and who is liar?











share|improve this question











$endgroup$







  • 3




    $begingroup$
    Just to clarify a few things: 1. Do the liars have to put down a specific number, or can they just write down any number at all as long as it’s not the number of people they danced with? 2. Does the king participate in the dancing? Thanks!
    $endgroup$
    – PiIsNot3
    Mar 27 at 9:37






  • 1




    $begingroup$
    1. Everyone can type whatever he/she wants as long as it's truth or lie. 2. Doesn't matter if king danced at all.
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 9:47











  • $begingroup$
    Is the King lying? What does a truth-teller say about dancing with the King?
    $endgroup$
    – Weather Vane
    Mar 27 at 9:52











  • $begingroup$
    Got the right answer, but even if the king was liar/truth teller it would still fit in, but no he didn't dance at all, he dislikes dancing.
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 9:57













10












10








10


2



$begingroup$


A king goes to an island, where there are 5823 people who always tell the truth and 8723 who always lie.



The king is special guest for the party celebrating 2053 year.



On the party, liars and truth tellers dance in couples (everyone can dance with everyone), some people leave the dance, others join and some don't even participate in the dances as they are not dance lovers.



After the party, the king asked everyone who had danced on the party, how many truth tellers did he dance with and put the numbers into his diary.
Surprisingly, when he checked his diary later on, he found out he had all the numbers from 0 to 956 typed in uniquely.




How many truth tellers danced on the party, assuming everyone knows who is truth teller and who is liar?











share|improve this question











$endgroup$




A king goes to an island, where there are 5823 people who always tell the truth and 8723 who always lie.



The king is special guest for the party celebrating 2053 year.



On the party, liars and truth tellers dance in couples (everyone can dance with everyone), some people leave the dance, others join and some don't even participate in the dances as they are not dance lovers.



After the party, the king asked everyone who had danced on the party, how many truth tellers did he dance with and put the numbers into his diary.
Surprisingly, when he checked his diary later on, he found out he had all the numbers from 0 to 956 typed in uniquely.




How many truth tellers danced on the party, assuming everyone knows who is truth teller and who is liar?








mathematics liars






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Mar 27 at 9:54









jafe

25.1k472249




25.1k472249










asked Mar 27 at 9:25









Kradec na kysmetKradec na kysmet

817




817







  • 3




    $begingroup$
    Just to clarify a few things: 1. Do the liars have to put down a specific number, or can they just write down any number at all as long as it’s not the number of people they danced with? 2. Does the king participate in the dancing? Thanks!
    $endgroup$
    – PiIsNot3
    Mar 27 at 9:37






  • 1




    $begingroup$
    1. Everyone can type whatever he/she wants as long as it's truth or lie. 2. Doesn't matter if king danced at all.
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 9:47











  • $begingroup$
    Is the King lying? What does a truth-teller say about dancing with the King?
    $endgroup$
    – Weather Vane
    Mar 27 at 9:52











  • $begingroup$
    Got the right answer, but even if the king was liar/truth teller it would still fit in, but no he didn't dance at all, he dislikes dancing.
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 9:57












  • 3




    $begingroup$
    Just to clarify a few things: 1. Do the liars have to put down a specific number, or can they just write down any number at all as long as it’s not the number of people they danced with? 2. Does the king participate in the dancing? Thanks!
    $endgroup$
    – PiIsNot3
    Mar 27 at 9:37






  • 1




    $begingroup$
    1. Everyone can type whatever he/she wants as long as it's truth or lie. 2. Doesn't matter if king danced at all.
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 9:47











  • $begingroup$
    Is the King lying? What does a truth-teller say about dancing with the King?
    $endgroup$
    – Weather Vane
    Mar 27 at 9:52











  • $begingroup$
    Got the right answer, but even if the king was liar/truth teller it would still fit in, but no he didn't dance at all, he dislikes dancing.
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 9:57







3




3




$begingroup$
Just to clarify a few things: 1. Do the liars have to put down a specific number, or can they just write down any number at all as long as it’s not the number of people they danced with? 2. Does the king participate in the dancing? Thanks!
$endgroup$
– PiIsNot3
Mar 27 at 9:37




$begingroup$
Just to clarify a few things: 1. Do the liars have to put down a specific number, or can they just write down any number at all as long as it’s not the number of people they danced with? 2. Does the king participate in the dancing? Thanks!
$endgroup$
– PiIsNot3
Mar 27 at 9:37




1




1




$begingroup$
1. Everyone can type whatever he/she wants as long as it's truth or lie. 2. Doesn't matter if king danced at all.
$endgroup$
– Kradec na kysmet
Mar 27 at 9:47





$begingroup$
1. Everyone can type whatever he/she wants as long as it's truth or lie. 2. Doesn't matter if king danced at all.
$endgroup$
– Kradec na kysmet
Mar 27 at 9:47













$begingroup$
Is the King lying? What does a truth-teller say about dancing with the King?
$endgroup$
– Weather Vane
Mar 27 at 9:52





$begingroup$
Is the King lying? What does a truth-teller say about dancing with the King?
$endgroup$
– Weather Vane
Mar 27 at 9:52













$begingroup$
Got the right answer, but even if the king was liar/truth teller it would still fit in, but no he didn't dance at all, he dislikes dancing.
$endgroup$
– Kradec na kysmet
Mar 27 at 9:57




$begingroup$
Got the right answer, but even if the king was liar/truth teller it would still fit in, but no he didn't dance at all, he dislikes dancing.
$endgroup$
– Kradec na kysmet
Mar 27 at 9:57










1 Answer
1






active

oldest

votes


















10












$begingroup$

I think that the answer is




Just $1$ truthteller danced.




Reasoning




Suppose more than one truthteller dances, say $N$. Now consider the graph of dancers just involving truthtellers, where an edge represents "danced with". Within this graph, either the lowest degree of a node is $0$, where then the highest possible is $N-2$, or the lowest degree is $1$, where the highest possible is $N-1$. In either case, by the Pigeonhole Principle, there will be at least two truthtellers who report the same number to the king. Of course, if there are zero truthtellers who danced then one of the liars would have to have told the truth - saying $0$.




Proof that this works




Suppose there is $1$ truthteller, he will report $0$. There just needs to be one liar who doesn't dance with the truthteller who reports $1$. Then everyone else is verifiably lying.







share|improve this answer









$endgroup$












  • $begingroup$
    That's it, that was fast even with all the baits I put.
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 9:57










  • $begingroup$
    @Kradecnakysmet Thanks, I was thrown for a second by the numbers and thought there might be a large number of solutions.
    $endgroup$
    – hexomino
    Mar 27 at 9:59










  • $begingroup$
    I will admit I was laughing while typing all those random numbers :D
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 10:00











Your Answer





StackExchange.ifUsing("editor", function ()
return StackExchange.using("mathjaxEditing", function ()
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
);
);
, "mathjax-editing");

StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "559"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);

else
createEditor();

);

function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);



);













draft saved

draft discarded


















StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fpuzzling.stackexchange.com%2fquestions%2f81070%2fisland-of-liars%23new-answer', 'question_page');

);

Post as a guest















Required, but never shown

























1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









10












$begingroup$

I think that the answer is




Just $1$ truthteller danced.




Reasoning




Suppose more than one truthteller dances, say $N$. Now consider the graph of dancers just involving truthtellers, where an edge represents "danced with". Within this graph, either the lowest degree of a node is $0$, where then the highest possible is $N-2$, or the lowest degree is $1$, where the highest possible is $N-1$. In either case, by the Pigeonhole Principle, there will be at least two truthtellers who report the same number to the king. Of course, if there are zero truthtellers who danced then one of the liars would have to have told the truth - saying $0$.




Proof that this works




Suppose there is $1$ truthteller, he will report $0$. There just needs to be one liar who doesn't dance with the truthteller who reports $1$. Then everyone else is verifiably lying.







share|improve this answer









$endgroup$












  • $begingroup$
    That's it, that was fast even with all the baits I put.
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 9:57










  • $begingroup$
    @Kradecnakysmet Thanks, I was thrown for a second by the numbers and thought there might be a large number of solutions.
    $endgroup$
    – hexomino
    Mar 27 at 9:59










  • $begingroup$
    I will admit I was laughing while typing all those random numbers :D
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 10:00















10












$begingroup$

I think that the answer is




Just $1$ truthteller danced.




Reasoning




Suppose more than one truthteller dances, say $N$. Now consider the graph of dancers just involving truthtellers, where an edge represents "danced with". Within this graph, either the lowest degree of a node is $0$, where then the highest possible is $N-2$, or the lowest degree is $1$, where the highest possible is $N-1$. In either case, by the Pigeonhole Principle, there will be at least two truthtellers who report the same number to the king. Of course, if there are zero truthtellers who danced then one of the liars would have to have told the truth - saying $0$.




Proof that this works




Suppose there is $1$ truthteller, he will report $0$. There just needs to be one liar who doesn't dance with the truthteller who reports $1$. Then everyone else is verifiably lying.







share|improve this answer









$endgroup$












  • $begingroup$
    That's it, that was fast even with all the baits I put.
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 9:57










  • $begingroup$
    @Kradecnakysmet Thanks, I was thrown for a second by the numbers and thought there might be a large number of solutions.
    $endgroup$
    – hexomino
    Mar 27 at 9:59










  • $begingroup$
    I will admit I was laughing while typing all those random numbers :D
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 10:00













10












10








10





$begingroup$

I think that the answer is




Just $1$ truthteller danced.




Reasoning




Suppose more than one truthteller dances, say $N$. Now consider the graph of dancers just involving truthtellers, where an edge represents "danced with". Within this graph, either the lowest degree of a node is $0$, where then the highest possible is $N-2$, or the lowest degree is $1$, where the highest possible is $N-1$. In either case, by the Pigeonhole Principle, there will be at least two truthtellers who report the same number to the king. Of course, if there are zero truthtellers who danced then one of the liars would have to have told the truth - saying $0$.




Proof that this works




Suppose there is $1$ truthteller, he will report $0$. There just needs to be one liar who doesn't dance with the truthteller who reports $1$. Then everyone else is verifiably lying.







share|improve this answer









$endgroup$



I think that the answer is




Just $1$ truthteller danced.




Reasoning




Suppose more than one truthteller dances, say $N$. Now consider the graph of dancers just involving truthtellers, where an edge represents "danced with". Within this graph, either the lowest degree of a node is $0$, where then the highest possible is $N-2$, or the lowest degree is $1$, where the highest possible is $N-1$. In either case, by the Pigeonhole Principle, there will be at least two truthtellers who report the same number to the king. Of course, if there are zero truthtellers who danced then one of the liars would have to have told the truth - saying $0$.




Proof that this works




Suppose there is $1$ truthteller, he will report $0$. There just needs to be one liar who doesn't dance with the truthteller who reports $1$. Then everyone else is verifiably lying.








share|improve this answer












share|improve this answer



share|improve this answer










answered Mar 27 at 9:54









hexominohexomino

45.6k4140219




45.6k4140219











  • $begingroup$
    That's it, that was fast even with all the baits I put.
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 9:57










  • $begingroup$
    @Kradecnakysmet Thanks, I was thrown for a second by the numbers and thought there might be a large number of solutions.
    $endgroup$
    – hexomino
    Mar 27 at 9:59










  • $begingroup$
    I will admit I was laughing while typing all those random numbers :D
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 10:00
















  • $begingroup$
    That's it, that was fast even with all the baits I put.
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 9:57










  • $begingroup$
    @Kradecnakysmet Thanks, I was thrown for a second by the numbers and thought there might be a large number of solutions.
    $endgroup$
    – hexomino
    Mar 27 at 9:59










  • $begingroup$
    I will admit I was laughing while typing all those random numbers :D
    $endgroup$
    – Kradec na kysmet
    Mar 27 at 10:00















$begingroup$
That's it, that was fast even with all the baits I put.
$endgroup$
– Kradec na kysmet
Mar 27 at 9:57




$begingroup$
That's it, that was fast even with all the baits I put.
$endgroup$
– Kradec na kysmet
Mar 27 at 9:57












$begingroup$
@Kradecnakysmet Thanks, I was thrown for a second by the numbers and thought there might be a large number of solutions.
$endgroup$
– hexomino
Mar 27 at 9:59




$begingroup$
@Kradecnakysmet Thanks, I was thrown for a second by the numbers and thought there might be a large number of solutions.
$endgroup$
– hexomino
Mar 27 at 9:59












$begingroup$
I will admit I was laughing while typing all those random numbers :D
$endgroup$
– Kradec na kysmet
Mar 27 at 10:00




$begingroup$
I will admit I was laughing while typing all those random numbers :D
$endgroup$
– Kradec na kysmet
Mar 27 at 10:00

















draft saved

draft discarded
















































Thanks for contributing an answer to Puzzling Stack Exchange!


  • Please be sure to answer the question. Provide details and share your research!

But avoid


  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.

Use MathJax to format equations. MathJax reference.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fpuzzling.stackexchange.com%2fquestions%2f81070%2fisland-of-liars%23new-answer', 'question_page');

);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







-liars, mathematics

Popular posts from this blog

Mobil Contents History Mobil brands Former Mobil brands Lukoil transaction Mobil UK Mobil Australia Mobil New Zealand Mobil Greece Mobil in Japan Mobil in Canada Mobil Egypt See also References External links Navigation menuwww.mobil.com"Mobil Corporation"the original"Our Houston campus""Business & Finance: Socony-Vacuum Corp.""Popular Mechanics""Lubrite Technologies""Exxon Mobil campus 'clearly happening'""Toledo Blade - Google News Archive Search""The Lion and the Moose - How 2 Executives Pulled off the Biggest Merger Ever""ExxonMobil Press Release""Lubricants""Archived copy"the original"Mobil 1™ and Mobil Super™ motor oil and synthetic motor oil - Mobil™ Motor Oils""Mobil Delvac""Mobil Industrial website""The State of Competition in Gasoline Marketing: The Effects of Refiner Operations at Retail""Mobil Travel Guide to become Forbes Travel Guide""Hotel Rankings: Forbes Merges with Mobil"the original"Jamieson oil industry history""Mobil news""Caltex pumps for control""Watchdog blocks Caltex bid""Exxon Mobil sells service station network""Mobil Oil New Zealand Limited is New Zealand's oldest oil company, with predecessor companies having first established a presence in the country in 1896""ExxonMobil subsidiaries have a business history in New Zealand stretching back more than 120 years. We are involved in petroleum refining and distribution and the marketing of fuels, lubricants and chemical products""Archived copy"the original"Exxon Mobil to Sell Its Japanese Arm for $3.9 Billion""Gas station merger will end Esso and Mobil's long run in Japan""Esso moves to affiliate itself with PC Optimum, no longer Aeroplan, in loyalty point switch""Mobil brand of gas stations to launch in Canada after deal for 213 Loblaws-owned locations""Mobil Nears Completion of Rebranding 200 Loblaw Gas Stations""Learn about ExxonMobil's operations in Egypt""Petrol and Diesel Service Stations in Egypt - Mobil"Official websiteExxon Mobil corporate websiteMobil Industrial official websiteeeeeeeeDA04275022275790-40000 0001 0860 5061n82045453134887257134887257

Frič See also Navigation menuinternal link

Identify plant with long narrow paired leaves and reddish stems Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern) Announcing the arrival of Valued Associate #679: Cesar Manara Unicorn Meta Zoo #1: Why another podcast?What is this plant with long sharp leaves? Is it a weed?What is this 3ft high, stalky plant, with mid sized narrow leaves?What is this young shrub with opposite ovate, crenate leaves and reddish stems?What is this plant with large broad serrated leaves?Identify this upright branching weed with long leaves and reddish stemsPlease help me identify this bulbous plant with long, broad leaves and white flowersWhat is this small annual with narrow gray/green leaves and rust colored daisy-type flowers?What is this chilli plant?Does anyone know what type of chilli plant this is?Help identify this plant