The Stack Overflow podcast is back! Listen to an interview with our new CEO.

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).

Filter by
Sorted by
Tagged with
1
vote
3answers
636 views

Who broke it. 3 person logic

D walks into a room and sees his computer is broken. He asks "Who broke my computer?". A says B did it B says A is lying C says he did not Of the three, it is known that only one is ...
6
votes
10answers
1k 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?
27
votes
6answers
5k views

Out of these 20 Doors, Which One Leads You to the Jackpot?

Congratulations for achieving this final stage of "Millionaire Super Logic" show! Once again, my name is Athin, and I'll be your host to help you win the jackpot of one, milLION, DOLLARS! *audience ...
21
votes
6answers
4k views

The Knight never lies, the knave always lies, and the spy either lies or tells the truth

A says he is not the knight, B says he is not a spy, and C says he is not the knave. Who is who?
19
votes
4answers
6k views

Who stole the flying car in Hogwarts?

During a trial in a Hogwarts court, Ron claimed that the Flying Ford Anglia car was stolen by Hermione. Then Hermione and Harry gave testimonies which, for some reason, were not recorded. Later on ...
7
votes
6answers
2k views

Contradictional Ceremony Puzzle

Can you find out who is the killer behind this wedding ceremony case? Your friend asked you to attend a wedding ceremony of his younger brother, Mike. The ceremony ran smoothly and lively. Mike and ...
4
votes
5answers
693 views

Who broke Mrs. Smith's kitchen window?

you are a detective in the local neighborhood. Four windows have been broken: the school's window, Mrs. Smith's kitchen window, Mr. Brown's car window, and the police officer's window. The four ...
-1
votes
2answers
292 views

Round tabel conference with liars?

In a conference, 8 People sit in a round table all pointing inwards .They are A,B,C,D,E,F,G and H. 3 people out the 8 people always lie .While others always speaks truth . Here are there 8 ...
32
votes
10answers
6k views

Liar liar pants on fire

Here is an easy and straightforward liar puzzle. Four people are in a room, stack reader, boboquack, Rand al'Thor and Brent Hackers. stack reader states that at least 2 of the other 3 are liars. ...
6
votes
3answers
845 views

How would one make a good liars puzzle?

I’ve seen and made a few liars puzzles, and a recurring theme with liars puzzles is that they can be too easy, and can be dull, perhaps a bit repetitive. How can you come up with a Liars puzzle that ...
3
votes
2answers
238 views

Where’s my present?

sequel of: Which of my friends has a birthday today? Hello. It's me again. Today is my birthday! So of course I met my friends today, along with a new friend that I made the other day. This new ...
6
votes
3answers
579 views

Which of my friends has a birthday today?

I have five close friends, Andrew, Benjamin, Cassie, Danielle and Eric. I know that one of them has a birthday today but I can't remember which. I asked Andrew who had a birthday today, and he ...
4
votes
1answer
389 views

Are all “Who did it?” puzzles the same?

I recently came across this puzzle here and several others not on Stack Exchange, which seem to follow a common pattern I call "Who did it?" for now. "Who did it?" does not refer to any puzzle ...
28
votes
7answers
10k views

Who killed Jeremy?

Jeremy was killed. Peter claims that Tom is guilty. Tom says that Ralph is guilty. John swears he didn't kill Jeremy. Ralph says that Tom is lying. If only one person is telling the ...
-2
votes
3answers
591 views

Which teacher is telling the truth?

It is generally known that lecturers for some course either always tell the truth or always lie. Arthur and Ignaz are those lecturers. Arthur says: "Exactly one of us is lying". Ignaz says: "...
5
votes
6answers
680 views

You meet Yessayer, Nosayer, Truther, Liar

You meet 4 persons you haven't seen before, and must ask questions to determine who is who.They know each other, and their friends' behaviour. You may ask each as many times as you want but only yes/...
9
votes
6answers
4k views

Solve the following knights and knaves problem

A says: “B is a knave.” B says: “A and C are of the same type.” Knights tell the truth and Knaves lie. What is C? (i.e. a knight, or a knave?)
38
votes
3answers
11k views

How many liars are in the room?

There are five people in a room. Each person is either a knight, who always tells the truth, or a liar, who always lies. Each person is asked the following question: How many liars are among you?...
35
votes
12answers
9k views

Batman vs 4 villains

One day after having his morning Bat-coffee, Batman received the following message on his Bat-computer: Hello there Dark Knight. I, the Riddler, along with Joker, Two-Face, and Penguin, are ...
5
votes
1answer
336 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 ...
13
votes
9answers
4k views

Three boxes, Four questions, Three times not true, Once the truth

There are 3 boxes, only one of which contains a treasure. The guardian will only answer you truthfully once, the other three times he will lie. You may ask 4 YES or NO questions. Which questions ...
17
votes
4answers
2k views

Can anything be deduced from the statement “If I am a truth teller, the other two are liars”?

There is a scenario which goes along the following lines: There are three friends. The friends are either truth tellers, or liars. One friend makes the statement: "If I am a truth teller, the ...
10
votes
6answers
2k views

Three Doors Logic Puzzle

One day you wake up in a strange room with no windows and three exits (don't ask why, you just do). Between you and the doors is a very moody looking guard who will no doubt kick your ass if you try ...
4
votes
9answers
2k 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.
-5
votes
4answers
518 views

Knights Knaves and Spies

There are inhabitants of an island on which there are three kinds of people: Knights who always tell the truth Knaves who always lie Spies who can either lie or tell the truth. You encounter three ...
4
votes
1answer
2k views

Alternate answer to the 2 guard 2 door question?

I asked a friend the classic question about the two guards and two doors that goes as follows: The rules are clear: there are two doors. One leads to the castle, the other, to certain death. You may ...
3
votes
1answer
546 views

Who lies and who tells the truth?

Six PLK secret agents are arrested and interrogated for several days. An agent tells the truth when all his statements are true, otherwise he lies. A report is drawn up containing the following ...
8
votes
7answers
4k views

Stolen Computer [duplicate]

A retail businessman had his computer stolen. The thief had to be Ruma, Jennifer, Djokovic, Tuhin, or Monisha. When questioned, each executive made three statements: Ruma (a) I didn't take the ...
8
votes
3answers
485 views

Hired by the Council of Magic - Language Barrier at the Circle

Hired by the Council of Magic - Language Barrier at the Circle: After your two successful visits to call upon the aid of the Council of Magic, the Council has called in one of the favors the King of ...
7
votes
4answers
1k views

Knight and knave impostors!

While on some adventure, you are transported away from your companion magically. Your companion, confused, enters a nearby building that suddenly materialised overnight. Inside the building there is ...
6
votes
3answers
1k views

Telling the truth or lying?

There are two men, Bob and Dylan. Bob says “One of the two of us is a liar”. Dylan says “Actually, we’re both liars”. Honest men always tell the truth and liars always lie. What are these men? Both ...
7
votes
2answers
680 views

What did he say he said? Liars with a twist!

5 shy dudes who can never talk for themselves stand in a circle. Every time you ask one of them a question, the dude to their right will answer for them. 3 of them always lie and 2 of them always tell ...
-1
votes
3answers
202 views

Boxed AI, Ethics, and Chivalry, oh my

(Inspired by this somewhat) So, your science lab is on the forefront of super AI. However they may not be on the forefront of good AI. Hence the AI is in a box until they can figure out what to do ...
10
votes
5answers
601 views

Liars of El Dorado

After a lifetime of searching, you have discovered the legendary city of El Dorado. You are approached by three inhabitants. You know from your research that these are the three highest ranking ...
22
votes
4answers
2k views

Art Accident at Airport!

There was an accident at the airport! A hanging art installation fell and landed on some passengers. In addition to tearing up all their tickets and mixing up their luggage, six people sustained ...
3
votes
1answer
331 views

The Lying Servers

You have 4 servers which accept a positive number from 0 to 255 (8 bits). Each server takes it's input, performs a basic addition or subtraction of a single digit, non-zero number, and outputs the ...
10
votes
3answers
502 views

Convoluted Logic Puzzles 101 and 102

I need some help. I'm registered for two courses at the Louisiana Institute of Epistemology this semester, but the TA's are super hard to communicate with! Can you help figure out where my classes ...
11
votes
2answers
1k views

Name the trolls

TL;DR There are 11 trolls named and you should discover their names by asking yes-or-no questions to them, directing each question to one troll. You must use the minimum possible number of questions. ...
13
votes
4answers
2k views

Incoming enemy! Scout, dispatch! [duplicate]

You are the leader in a group of 9 scouts. There are rumors of an incoming enemy army and your unit was sent to investigate where they are coming from. You are aware that there are only 4 ...
15
votes
5answers
3k views

Who led the mutiny?

You are were might still be a sea captain. On the 14th of December, 1214, your sailors rebelled. 6 sailors and your first mate get in a boat to row you to what they believe is an abandoned island. ...
26
votes
5answers
5k views

You trolls, get out of my party!

You have invited $2017$ of your acquaintances to a party. But after they all arrive, you come to know from a reliable source that each of your guests is either a troll or a true friend. You don't know ...
-3
votes
2answers
609 views

3 guards, 3 objects, 3 monsters and 3 questions

You are standing before 3 objects. You need to give the right one to the right monster or else you'll die. There are 3 people in front of you for you to question. One always lies, one always tells ...
20
votes
5answers
2k views

Knights and knaves in Landilandia

You're traveling on a hiking trip in the land of Landilandia when you encounter a forest. The notes in your guidebook tell you that there's a safe route here leading into the woods, but when you ...
22
votes
3answers
2k views

The last question to the guards

"What will happen next?" asked the old man. His voice was friendly, his eyes bright, as always. His hair and beard seemed to be even whiter than ever before. "The standard procedure is as follows: ...
6
votes
1answer
652 views

Identify truth-teller amongst tricksters

There are 27 people. At least half of them are truth-tellers, others are tricksters. Tricksters can answer yes/no regardless of your question. But we should ask them such questions that truth-tellers ...
5
votes
3answers
310 views

Sixteen Castaways

Note: This was reposted from Knossos Games. I am not affiliated with the site in any way, shape, or form. Marooned on a tropical island. Forced to send one fellow member of their ...
5
votes
5answers
2k views

Catch the liar(s). Prove it using a truth table

Alice: "If Bob is lying, Charlie is lying!" Bob: "If Charlie is lying, Alice is lying!" Charlie: "If Alice is lying, Bob is lying!" Who is/are lying? How do you prove it using a truth table?
4
votes
2answers
615 views

The Rapper's Crown?

You are running through a mysterious dungeon, when you see a large room, which you enter. Inside there is a man and a woman, one is a truth teller, and one a liar. However when they write they always ...
3
votes
6answers
2k views

Knights, Knaves and Normals - the tough one

I found this puzzle and I have difficulties to solve it: Imagine three people, Alice, Bob, Chris, each of whom is either a knight, a knave or a normal. Exactly one person in the group is a knight. ...
9
votes
6answers
3k views

Who stole the jewels?

Maybe you guys can help me with a puzzle. Only one of the following is telling the truth. Who stole the jewels? Frank: Marcus didn't steal the jewels. Marcus: Leon didn't steal the jewels. ...