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Questions tagged [liars]

Puzzles that focus on getting information from truth-tellers (who never lie), liars (who always lie), and Jokers (who answer at random).

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3
votes
2answers
584 views

How does a common man solve impossibly hard truthteller/falsifier questions?

How does one solve the World's hardest puzzle, and other questions of the type? Is there a proper approach to such a question, or does one just have to be incredibly smart to do so? And here's an ...
-3
votes
1answer
497 views

3 suspects Logic Puzzle [duplicate]

The following puzzle was posted here, but providing answers to the puzzle was closed without a correct and complete answer being provided: An inspector knows that exactly one of 3 suspects committed ...
4
votes
1answer
4k views

Is this a correct solution to determining which of two people is the liar using one question?

I was working my way through some Propositional Logic Questions in Discrete Maths by Rosen, when I came across the following question: An explorer is captured by a group of cannibals. There are two ...
0
votes
0answers
167 views

3 Gods Logic Puzzle [duplicate]

This logic puzzle can be found on the web so NO GOOGLING! You walk up to three gods. One always tells the truth, one always lies, and one randomly decides to tell the truth or to lie and does what ...
11
votes
2answers
765 views

The Three Seers

Your kingdom has been aided, for as long as anyone remembers, by three great seers. These seers are all-knowing and will truthfully answer one question of any person that seeks them. This question ...
17
votes
1answer
2k views

The Pirates of Beal Isle - very long logic grid puzzle

Story Let me tell ye a tale: Somewhere northeast o' the Bahamas there be a tiny scrap o' rocks stickin' up out o' the sea known as Beal Island. It be a barren, rocky place, and no man ever called it ...
25
votes
11answers
6k views

Kill the jokers! - Part 1

The famous and ruthless explorer Wyoming Wilbert reports in one of his books that he once visited an island inhabited by jokers and truth tellers. Truth tellers always tell the truth, whereas jokers ...
18
votes
4answers
2k views

Past, Present and Future

There are 3 gods, named Past, Present and Future, who all look identical. They sit in a throne room, with one in the middle, the others on the right and left. You are allowed to ask them a series of ...
0
votes
2answers
454 views

Is there probability based Knight-Knave puzzles?

Have you seen Knight-Knave puzzles based on probability rather then facts? For example a puzzle with condition like this: Knight tells the answer, probability to which according to his knowledge is ...
2
votes
2answers
2k views

Knights , Knaves and Spies - Part 2

I was working my way through some Knight and Knave Puzzles in Discrete Maths by Rosen, when I came across the following question: There are inhabitants of an island on which there are three kinds ...
3
votes
1answer
349 views

Ultimate family dart game

A family of 3 - a father, mother and son - are practising on a dart board. It has 3 shapes - a triangle, a circle and a square - on it. Scoring is as follows: Intersection of all 3 shapes - 5 points ...
17
votes
3answers
2k views

Lies, damned lies, and statistics

A (hopefully) new variant on the Knights & Knaves problem. On the island of D'Israel, the inhabitants fall into three types: Liars, Damned Liars, and Statisticians. They are visually ...
46
votes
10answers
16k views

Puzzle: Who hacked the computer?

I was working my way through some Knight and Knave Puzzles in Discrete Maths by Rosen, when I came across the following question: Four friends have been identified as suspects for an unauthorized ...
4
votes
2answers
923 views

Island inhabitants: Who lies and who tells the truth? [duplicate]

On some island, the population is split into native people and into outlanders. There are more natives than outlanders. Someone with extreme logical and mathematical thinking wants to know who are ...
6
votes
2answers
502 views

How many knights

In a room are 13 men, who are either Knights (truth tellers) or Knaves (lie tellers). the first man looks around and says "The number of knights in this room is no greater than one" the second man ...
16
votes
2answers
1k views

Automatically a Knight, Knave, and Joker

Let M be a finite positive integer. It's exact value is not known. Suppose we have three classes of automaton, all of which accept a bit stream as input, produce a bit stream as output (one bit per ...
0
votes
3answers
2k views

Puzzle : Who is Corrupt in the Senate?

I was working my way through some puzzles in Discrete Maths by Rosen, when I came across the following question: Freedonia has fifty senators. Each senator is either honest or corrupt. ...
21
votes
5answers
3k views

Knights and Knaves : Liar , Liar - How many are you?

There are 2014 persons in a row Each of them is either a Knave (who always lies) or a Knight (who always tells the truth). Each person says 'There are more knaves to my left than knights to my ...
7
votes
4answers
2k views

Lying, truthful and merciless guards (variation)

This is a variation of the riddle of 2 guards and 2 doors: You are stuck in a room with 3 doors. Each of the doors have a guard posted. One guard always tells the truth, one always lies, and the ...
9
votes
1answer
1k views

The Old Millionaire

A very old man has a million dollars, which he's going to pass down to you! He has 3 associates who have been ordered to help you. The 3 associates know the location where it is, and they tell you it ...
1
vote
2answers
530 views

If The Knights and Knaves got together [closed]

If the island of knights and knaves got together and there were n people, including a joker, how many questions would it take for all of the knights and knaves found the joker? Nobody knows who each ...
14
votes
1answer
2k views

Knights and knaves in a foreign language

You die and ascend to heaven, there is a knight (truth-teller), a knave (pure liar) and a joker (random) sitting on a cloud - they all look the same. In order to gain entry you must determine their ...
1
vote
1answer
262 views

T Knights, L Knaves and R Jokers with one question type only

I would like to try more strict conditions for puzzle, which frodoskywalker solved so simply. Basically all the same, but only one type of questions is allowed. We have T Knights (truth-tellers),...
4
votes
1answer
782 views

The knaves come out at night

Standard knights and knaves problem. There are 10 people in a room, you know that each person will either always tell the truth or always lie, but you don't know who is a truth teller or liar. You ...