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.
262
questions
6
votes
0answers
199 views
Trying to find a 2020 puzzle hunt with a puzzle based on Among Us
I am trying to find a puzzle hunt that I believe was held in 2020. It contained a puzzle based on the game Among Us with 26 characters, and you had to decide who were the imposters. The imposters all ...
8
votes
3answers
458 views
Which Demon Spoke?
While wandering, you encounter a pond, in which two demons are bathing. One is labelled 'honest', meaning they always tell the truth, and the other is labelled 'liar', which means they always lie. As ...
1
vote
1answer
424 views
Knight or Knave
On the island of knights and knaves (where knights always tell the truth and knaves lie), you meet two islanders named Penny and Quinru.
Penny: Both Quinru and I are knaves!
Who is a knight and who ...
11
votes
4answers
2k views
Who is the liar (Number of liars)?
There are 5 people. Each one can be lying or telling the truth, and they can't switch. Below, each person tells us how many liars exist in the group.
There are at least 3 liars.
There are at least 2 ...
7
votes
3answers
420 views
Can you find and capture a shapeshifter?
A town was invaded by aliens, and some of its residents were kidnapped and replaced by shapeshifters. You're tasked with capturing one of the shapeshifters. Here's the setup:
There are 7 residents of ...
4
votes
1answer
258 views
Trapped in an escape room with 2 liars
You are in a room, with 6 people. 2 of them are liars. The room has a code pad. The people say:
People
What they say
Keith
The first and last digit are the same number and are not used anywhere else ...
10
votes
3answers
430 views
We have captured 5 spies. Their names are A, B, C, D, and E
This is a variant of the puzzle here.
We have captured 5 spies belonging to a secret organization. Their identities are unknown; we only know them by their codenames A, B, C, D, and E. After thorough ...
-2
votes
1answer
98 views
Is asking your one question by doing an action an answer to the two doors, two guards puzzle? [closed]
Is asking your one question while doing an action an answer to the two doors, two guards puzzle? Example: You ask your one question by moving towards any door. Only the true guard will continue to ...
-2
votes
2answers
180 views
How many children wear a yellow t-shirt?
The puzzle is as follows:
In a certain kindergarten there are 23 children. Some of them wear a
green t-shirt, others a yellow t-shirt and others blue t-shirt. A tv
reporter who was on the site doing ...
1
vote
1answer
131 views
Knight can't answer about joker
If you ask a knight (True) about a Joker's answer (random), then she can't answer because she doesn't know?
Does this give a NaN response or is it not allowed?
I looked at similar questions and couldn'...
5
votes
2answers
512 views
The wrapping machines of Santa
Christmas is coming and Santa is working hard to wrap all the presents until the 24th of December.
He has six wrapping machines: A, B, C, D, E and F, that work $24/7$ all at the same time. But the ...
1
vote
2answers
130 views
Guess the hat colors - Riddle 6
And for today, a new original hat guessing puzzle!
CHALLENGE: Guess the hats of the 4 prisoners.
SPECIAL RULE: One of the prisoners is lying
DESCRIPTION: Each one can see the hats that are in front ...
9
votes
2answers
198 views
Great puzzle makers of yore: #1, Martin Hollis: “The Poacher's Funeral”
When Peter the Poacher died, his six direct descendants all came to the funeral, each being a son, grandson or great-grandson of the old reprobate. The "Chippings Post" sent a man to compile ...
5
votes
2answers
402 views
2 weird problems I came across
A man accused of murder hires a lawyer who is always believed by the court to be telling the truth. The prosecution's attorney says that if the accused man committed the murder, he had an accomplice. ...
3
votes
2answers
239 views
The ice cream puzzle
I am a new user, and I made this puzzle myself, but I lost the answer key, can anyone solve it so I can make a new one?
The owner of the ' Super Ice Cream' shop was terrified. One of his workers was ...
7
votes
3answers
620 views
One truthteller, one liar, and two randoms - least questions to identify?
I have landed on a new planet and there are 4 people there. One of them is a truth teller and they always speak the truth. The other is a liar and they always lie. The other 2 are random and they ...
8
votes
1answer
217 views
Mirror, mirror on the wall, who's the fairest of us all?
Three evil queens, accompanied by their magic mirrors, go for a girls' night out. At some point of the night they decide to finally settle the eternal question: who's the fairest of them all? Of ...
5
votes
4answers
1k 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).
-...
3
votes
3answers
341 views
Vampires, Insanity and Transylvanian Sisters
This is a puzzle from this site: https://medium.com/i-math/vampires-insanity-transylvanian-sisters-88ce3516fd
I thought it was very nice, so I wanted to share it with you. WARNING: the above link ...
10
votes
3answers
662 views
Eight campers and the right path
In the spirit of some of my Raymond Smullyan favorites, here's a relatively hard puzzle from a Dennis Shasha collection of $1988$:
Eight kids and their guide are lost on a forest exactly one hour ...
4
votes
6answers
1k views
Who broke the window? [closed]
There is a broken window in the house. I asked who broke the window:
Gregory: I was not!
April : I didn’t do it.
August: April was.
June : August says the truth
Two of them said the truth, and two ...
0
votes
3answers
125 views
City of Lies or Truth [duplicate]
Try to solve this one:
You are at an unmarked intersection ... one way is the City of Lies and another way is the City of Truth.
Citizens of the City of Lies always lie.
Citizens of the City of ...
4
votes
2answers
2k views
Two Truths and a Lie: a logic puzzle
I'm crafting an answer to the game Two Truths and a Lie: each person playing the game says three statements (usually about themselves, though I'm ignoring that requirement for this), two of which are ...
6
votes
1answer
254 views
Question which is sort of puzzle from mathematics Exam
I am self studying and trying questions of quantitative aptitude in my mathematics exam and I am unable to solve this problem.
Of three persons $A$, $B$ and $C$, one always lies while the others ...
20
votes
4answers
2k views
Boys and girls in a circle
There are $28$ students in a class, and each of them are either boy or girl. They sit in a circle, and claim that “The two people next to me are of different gender than each other.” It's known that ...
7
votes
1answer
454 views
Sane and crazy persons
I have found this puzzle on internet.
40 persons sit in a round table . All of them are either sane or crazy. When you ask a person "is the person sitting to your right sane or crazy?" a sane person ...
9
votes
3answers
672 views
Knight and Knaves Castle
I was pretty bored in the lockdown so I thought up a mathematics puzzle, which I haven's solved yet, so the community can solve together.
Let $n>1$ be a positive integer. There is a square castle ...
5
votes
3answers
381 views
Shocks and guesses
The Liar, the Random and Truth teller were captured and brainwashed to forget whether they always lie or tell truth or randomly answer.Everyone is handcuffed to a chair and gagged with gray, white and ...
1
vote
1answer
181 views
The Lying Brothers
The little town of Stackville is exactly like hundreds of other little communities in every respect but one. Its scenery, its stores, its churches all have their counterparts at every crossroads in ...
30
votes
5answers
2k views
How many spots do these frogs have?
You are approached by 5 spotted frogs who appear to be venomous, to avoid getting bitten by them, you must find out how many spots they have. The frogs with an even number of spots always tell the ...
3
votes
1answer
193 views
Fork in the road problem - with a single person
You walk to a fork from where two roads come out - one leading to a post office and the other to a university.
You want to go to the university, but do not know which road would lead you to it. A ...
7
votes
1answer
224 views
Two persons and one question “Is the shaman honest”. Which one of them is the shaman?
An anthropologist arrived to the shaman's den where there were two persons, one with a green hat and one with a blue hat. One of the shaman's students had said that there was a Star Predictor with the ...
6
votes
2answers
475 views
Smullyan Logic Puzzle about Nelson Goodman Principle - Knights and Knaves
In Smullyan's "Logical Labyrinths" there is the following problem 1.11:
...
8
votes
1answer
321 views
Constructing an island according to rules in Smullyan's “What is the Name of this Book”
I've recently finished dropping my jaw at Raymond Smullyan's "What is the Name of this Book," and the section on Gödel's incompleteness theorem, involving islands of knights (truthers) and knaves (...
2
votes
1answer
452 views
What is the smallest number of lies needed to solve a Dragon Joust puzzle?
I recently watched this video which presents a deduction "riddle" about dragon jousting. The rules for the puzzle (from the video) are as follows:
After centuries of war, the world’s ...
3
votes
8answers
707 views
Two doors, two guards, and two keys
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
(...
6
votes
1answer
277 views
The scales never lie (oh yes they do!)
There are $10$ coins, one of which is a fake, and weighs either more or less than the others - you don't know which.
There are two sets of scales - one tells the truth, the other lies (always says ...
13
votes
8answers
4k views
2 Guards, 3 Keys, 2 Locks
There are 2 guards: one only tells the truth, the other only lies.
There are 2 locks and 3 keys: each lock can only have 1 key matched - the 3rd key doesn't do anything.
You can only ask one ...
4
votes
2answers
321 views
Knights and knaves puzzler
A very special island is inhabited only by knights and knaves. Knights always tell the truth, and knaves always lie.
You meet three inhabitants: Peggy, Joe and Zippy.
Peggy claims, "I am a knight or ...
3
votes
2answers
274 views
Knight and knaves
A very special island is inhabited only by knights and knaves. Knights always tell the truth, and knaves always lie. You meet three inhabitants: Alice, Rex and Bob, where
Alice tells you that "Rex is ...
7
votes
4answers
530 views
Island of Knights, Knaves, Spies
There are 3 types of inhabitants of a village: knight, knaves, normal. You should map each inhabitant with its type, by asking only this type of question to a person:
"Hey X, what is the type of ...
1
vote
0answers
77 views
Survive from death by asking the right question twist [duplicate]
You are at a path and there is two roads splitting from it. The first one is certain death and the other is the way home. You do not know which way is the right way home, but there are two people. ...
35
votes
10answers
5k views
Knights and Knaves: What does C say?
You are on a fictional island with two types of people: knights who always tell the truth,
and knaves, who always lie. Three of the inhabitants - A, B, and C are standing in the
garden. A says, "B and ...
8
votes
12answers
3k views
Time to call the bluff [closed]
You are located outside of two rooms which have a door between them. Each room has one or more computers whose total power is unknown, so they cannot be reliably used as proof-of-work to compare times,...
5
votes
18answers
4k views
Ask one verbal question to figure out who is blind and who is mute among three persons
This is another "You can ask only one question" puzzle. This is an edited very restricted version
There may be multiple answers but I could come up with only one.
There are three persons in three ...
10
votes
2answers
308 views
Knights and Knaves on a (Not So) Deserted Island
One day, while flying your single-engine seaplane out over the Pacific, the electrical system shorts out, all of your electrical systems (including the radio) fail, and the engine dies. You are in a ...
2
votes
1answer
255 views
The chariot race
In a chariot race only 4 cars came to the finish: the blue, the green, the red and the white one.
Titus, who is in bed with a cold, inquires to Quintus about the outcome of the race, because he ...
12
votes
4answers
4k views
The joke office
Alice and Bob are supposed to get form A at the joke office.
Forms A, B, C, D and E are each at exactly one of the following five terminals. At one Terminal is only one form.
Terminal 1:
Here ...
14
votes
2answers
778 views
The alcoholic village festival
The villages Arriba and Abajo together have 2019 inhabitants.
At the annual festival are
more than 2000 villagers this year.
When they form a huge circle for dancing, everyone calls
happy: ...
21
votes
8answers
3k views
Robots in a spaceship [duplicate]
Xerxes has 6, 7 and 8-arm robots in his spaceship. Unfortunately, the 7-arm robots are misprogrammed and everything they say is a lie. The other robots are fine, they always speak the truth.
Once ...
