Questions tagged [liars]

Puzzles that focus on getting information from truth-tellers (who never lie), liars (who always lie), and/or Jokers (who answer at random), or which use such characters as an integral part of the puzzle.

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4 votes
1 answer
392 views

The Old Brazen Head

While walking through the forest, on the way to confess to your crush, you come upon an old house. Outside of this house is an old, damaged Brazen Head, with a hastily wired coin-slot appended beside ...
14 votes
4 answers
4k views

This logic puzzle is impossible!

Rocks always tell the opposite of a statement and Rolls tell the truth. If I was to tell you the following: A says C is a roll. A says there are 2 rocks. B says they are a roll. C says they are a ...
-4 votes
2 answers
112 views

Truths tellers and liars. A short one

On a strange island five people are living. Of the one half we know: they only speak the truth, of the other half we know: they only speak lies. How is that possible?
6 votes
4 answers
474 views

Get the treasure from an island of knights and a joker

You've learned that there's treasure buried somewhere on a small island, but not exactly where. The island is a perfect circle with a radius of 25 meters. There are 15 islanders there, one of whom is ...
1 vote
2 answers
120 views

Knights and Knaves [closed]

You are visiting an island with two types of people: knights who always tell the truth and knaves who always lie. From among the thousands of people who live on the island, you meet six people who ...
1 vote
1 answer
163 views

The Truth And Lies Today: Revisited

A man is only capable of telling the truth four hours a day. They are either TTFTT or TFTTT (equiprobable). For the other twenty hours, he lies. All hours between 7pm and 6am are night; 7am and 11am ...
3 votes
2 answers
378 views

I'm not a robot, I'm not a MONKEY

The city of Roboville has been invaded by robots, monkeys, and dancers, who will dance if the beat's funky. Some of the invaders can be two of them (e.g. both monkeys and robots) and some can be all ...
3 votes
2 answers
276 views

A logic puzzle with some lateral thinking

Original puzzle below created by me. The writing is... to be honest, not that good, but it's a puzzle. Focus on the puzzle part. Your name is John D. Tectif, and you're looking for 4 notorious ...
1 vote
0 answers
78 views

Truth, error, and random [duplicate]

There are three machines named "truth," "error," and "random" (but you don't know who they are). Among them, "truth" always tells the truth, "error" ...
1 vote
1 answer
166 views

Find Out Our Numbers (liars and truth-tellers)

You are an adventurer to a distant jungle that the news told you it was full on secrets. But, you could not find anything! So you decided to head home. When you were almost there, a troll (you ca't ...
-5 votes
1 answer
188 views

Police Interrogation Puzzle [closed]

I have tried so hard to solve this puzzle. But I cannot get my head around it. I have attempted to eliminate the lies and I have come up with Dave as the criminal. But I do not know if it is the ...
1 vote
1 answer
161 views

The Truth And Lies Today

Suppose a man only tells the truth three hours a day. It is the same every week and it is known that the pattern of the truth hours are TFTFT. (which means he may tell the truth at midnight and 2am ...
4 votes
4 answers
199 views

Constraint Satisfaction Problem: who killed Warren White?

Warren White was found shot dead one morning, police have then investigated who was behind the incident. There were 3 suspects who could be suspects in the incident. That afternoon, the 3 suspects ...
-1 votes
2 answers
110 views

Which day of the week is today (Tuesday, Wednesday, Saturday or Sunday) if one of the statements is false?

Today is neither Sunday nor Wednesday. Tomorrow is not Sunday or Wednesday. Yesterday was not Friday. Monday was not the day before yesterday, neither was Sunday. Which day of the week is today (...
7 votes
2 answers
563 views

Four boxes, four questions, only one truthful answer

This is a harder variant of the following question: Three boxes, Four questions, Three times not true, Once the truth The difference is that now there are four (not three) boxes, one of which ...
0 votes
2 answers
345 views

Is this Among Us logic puzzle possible? [closed]

In 11 Among Us players, some of them are crewmates, who always tell the truth, and imposters, who can either lie or tell the truth. Can you figure out who the imposters are? (There can be any number ...
4 votes
2 answers
575 views

You are left on a deserted island with 15 trolls

You are left on a deserted island with 15 trolls and you must identify who is who to leave. A tells the truth (truthful) B lies (liar) C always says yes (yes taker) D always says no (no taker) E says ...
5 votes
1 answer
187 views

Sobot or fauxbot?

Through the bustling hallway, you followed your speed-walking, speed-talking brother, who was hoping to submit an article about the upcoming demonstration to his beloved Logic and Philately Semi-...
6 votes
7 answers
2k views

Probability that truth is spoken on Thursdays

A man speaks the truth on only two days a week. The days are the same for each week and they are in the TFT form (TFT = True False True. This means that the days on which he speaks the truth are ...
3 votes
2 answers
529 views

7 Prisoners Say

Prisoner 3 says: "Prisoner 5, Prisoner 6 and I are truthful". Prisoner 6 says: "Prisoner 5 and Prisoner 1 are truthful". Prisoner 4 says: "Prisoner 7 lies". Prisoner 1 says: "...
10 votes
2 answers
419 views

How many times do the magicians' coats change color?

In a small town, there live 110 magicians, who can be identified by their magical color-changing coats. These magical coats turn green whenever the wearer tells the truth, and red whenever the wearer ...
3 votes
1 answer
208 views

Thieves for questioning

The police got three thieves when they tried to rob a bank. But the officer wants to give them a chance to get free, so he asks them who is the main brain behind the robbery. The thieves were puzzle ...
-3 votes
1 answer
141 views

2 blue eyes 99 red eyes

There are 101 normal people on an island. 2 have blue eyes and the rest have red eyes. The people with red eyes can leave the island. But the people with red eyes always tell the truth and the people ...
4 votes
1 answer
318 views

Puzzle 1.3 from Montague island mysteries

I'm on puzzle 1.3 "The Missing Painting" in the book Montague island mysteries I'm really struggling to understand the part in Taylor's instructions that says Keep in mind that a ...
22 votes
3 answers
7k views

The village of the liars and truth-tellers

I read this puzzle in an Italian newspaper some days ago. It reported it was asked at one of the latest Mathematical Olympiads. It's not difficult, but it requires some logical thinking. I'm posting ...
7 votes
1 answer
409 views

Identify someone as a truth-teller, liar or toggler with one yes/no question

You are visiting an island and need some information. The island has liars, truth-tellers, and togglers. Critically, togglers alternate truths and lies in their answers. When you meet someone, how can ...
28 votes
2 answers
3k views

Liar Wordle - Yet Another Wordle Variant!

In Liar Wordle, standard rules apply except each row contains exactly one clue of the wrong colour. For instance if we consider only the first row the correct colours could be Y-B-B-B-Y and the ...
4 votes
1 answer
224 views

The age of three ladies

Three ladies A, B and C have a discussion, where each lady says the truth twice and lies once. A: B is two years older than me B: C is 38 years old C: A is older than me B: The age difference between ...
5 votes
11 answers
2k views

Knights and Knaves Puzzle

On the island of knights and knaves, one of the inhabitants says "If I am a knight, then I will eat my hat." Will the inhabitant eat his hat?
3 votes
1 answer
231 views

Choose your guardian wisely!

I must issue a word of caution dear traveler. As your journey nears its end, you have one final obstacle to overcome. Ahead lies the gate of the guardians. As you might suspect, the gate is protected ...
7 votes
9 answers
730 views

The Land of Truth and Lies [closed]

You live in The Land of Truth and Lies, where any of your statements may be inverted in meaning, without prior warning. For example, if you intend to say "You're looking good today", you may ...
24 votes
11 answers
6k views

Who robbed the store?

You are investigating a shop robbery. The CCTV footage shows that there was one criminal, but it doesn't show their face. There are 10 suspects and you know that one of them is the criminal. The ...
118 votes
16 answers
1.4m views

Two doors with two guards - one lies, one tells the truth

You are a prisoner in a room with 2 doors and 2 guards. One of the doors will guide you to freedom and behind the other is a hangman–you don't know which is which. One of the guards always tells the ...
0 votes
2 answers
331 views

How many liars were there at the party? [duplicate]

Andy’s birthday party has just been moved up by a week. All the toys in Andy’s room are worried about being replaced by fancy new toys. Sheriff Woody, Andy’s favourite toy, and the others are waiting ...
4 votes
5 answers
2k views

One truthteller/liar and one random person

You come across two peculiar aliens: Alice and Bob. You know the following about them: -Alice is either a "truthteller" (she always tells the truth) or a "liar" (she always lies). -...
-1 votes
1 answer
322 views

A one liner question for marriage to a beautiful girl [closed]

Question: One day I saw an extremely beautiful lady on this island which consisted of only knights (that always are truthful) and knaves (that always lie) and was immediately smitten with her. I ...
1 vote
1 answer
243 views

Magicians, Knights and Knaves

My solution for this puzzle did not well match with the book's solution. I thought it would be good to check my argument's reasoning, though you can also propose your own answer. There is an island ...
1 vote
2 answers
262 views

Organs of the Enterpeton

An enterpeton has arrived at the bathhouse. Enterpetons are strange reptiles with exposed organs. Four of these organs can answer questions, and follow certain rules. These organs are: the heart, ...
-7 votes
1 answer
141 views

The Ultimate Liars

At the bathhouse, 27 travellers arrive. According to a book they have brought, each one follows a different one of the following rules: Traveller Yes Unknown No Sheep Y Y Y Knightly Sheep Y Y R ...
5 votes
2 answers
234 views

Knight-Knave-Normal Meta-Knowledge

A traveller visited one of the islands described by Raymond Smullyan on which all inhabitants are either knights, who always tell the truth, knaves, who always lie, or normals, who can say anything. ...
6 votes
1 answer
260 views

The Serpent-Tail

After defeating the octangular spirits, you find yourself needing some laundry powder. However, you can't find any at your usual shop, and so you have to ask one of the employees, who happens to be a ...
3 votes
1 answer
256 views

The Eight Spirits

After your ordeal with the enterpeton, you need the toilet. Unfortunately, your ability to urinate has been stolen by one of the octangular spirits, a set of spirits that follow strange rules. The ...
-1 votes
2 answers
161 views

The Rainbow Serpents

At your bathhouse job, you encounter a pair of rainbow serpents, each having two heads, hiding behind a wide pillar. They seem to be bent around the pillar with a head from each serpent visible on ...
3 votes
2 answers
311 views

Cursed Knights and Knaves

You are packing up after a week-long stay at the Verity Inn. You came here, to Truth Town, to visit your friend but now it's time to go home. You feel in good spirits as you pack your bags. As you are ...
4 votes
10 answers
3k views

Choose the right door for golds

Choose the right door for golds. Do it very carefully. If you choose the wrong door you will be dead.
3 votes
1 answer
467 views

Murder Mystery Question from an Entrance Exam

Here is a question I've been having some trouble with. I'd love any of your thoughts. It is Question 3 in this entrance exam. Mr Cadbury was murdered last night. Exactly one of six suspects is ...
1 vote
3 answers
579 views

The Third Hardest Logic Puzzle in the World

This puzzle is heavily derived from the Second Hardest Logic Puzzle in the World, which I also created. The current puzzle and the aforementioned are not identical, however. You have 5 guards: one ...
-3 votes
1 answer
263 views

How can a liar and a truthteller prove their identities? [closed]

You come across two people. One is a liar who always lies and the other is a truthteller who always tell the truth. You don't know who is who though. Both these people are allowed to say one sentence ...
32 votes
2 answers
3k views

The Second Hardest Logic Puzzle in the World

This puzzle is an original creation of mine (as far as I know), although other people have solved it before me. You meet five people: Alice, Bob, Carol, Daniel and Evie. Your aim is to ask yes/no ...
15 votes
2 answers
3k 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 ...

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