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More ways to get Braingle...

Liars and Truth Tellers

Logic puzzles require you to think. You will have to be logical in your reasoning.

 

Puzzle ID:#519
Fun:*** (2.63)
Difficulty:** (1.87)
Category:Logic
Submitted By:kaila912***
Corrected By:boodler

 

 

 



You approach two magic talking doors. One door leads to the City of Truth, while the other door leads to the City of Liars. You do not know which door is which. You are able to ask only one question to determine which door is which. The door that leads to the City of Liars always speaks lies, while the door that leads to the City of Truth always speaks the truth. You want to go to the City of Truth. What question do you ask to determine which door leads to the City of Truth?




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Comments

Mike1313*
Sep 10, 2001

Your answer #2 would not work because if you asked the door to the city of liars that question, he would still lie and tell you the wrong one. The fact that you rephrase the question doesn't make it any different from the question. "Which door is the door to the city of truths?"
maneesh
Nov 22, 2001

Answer #2 will also work because if he had ask the question to lier door he would have lied but if he is asking what would be his reply he will lie again and two lies will lead to truth.
sinazucar
Jan 30, 2002

Answer1:

Q: Mr. Door, if I were to ask the other door which door leads to the city of truth, what would he say?

A: (LIE) MINE!

-or-

Q: Mr. Door, if I were to ask the other door which door leads to the city of truth, what would he say?

A: (TRUTH) HIS!



Answer2:

Q: Mr. Door, what would you have told me if I had asked you which door lead to the city of truth.

A: (LIE) HIS!

-or-

Q: Mr. Door, what would you have told me if I had asked you which door lead to the city of truth.

A: (TRUTH) MINE!



How clever!

sinazucar
Jan 30, 2002

Wait a minute... this is flawed.

If I asked a door, "What's my name?"

The truth sayer would either say, "I don't know" or tell me my name.

The lying one would make up a name because it couldn't admit that it didn't know. And "I'm not telling you" isn't a lie unless he actually tells me my real name shortly after.

I could stump it with Bilbo's famous riddle too. What have I in my pocket?
lizard450*
May 28, 2002

yes the question is flawed ... you should state that the door that tells lies can lead to the city of truth or not and vice versa..
SkEwL_gUrl*
Jul 26, 2002

I've heard other variations of this teaser but this is the worst.
Rowsdower**
Jan 12, 2004

David Bowie was creepy in the movie "Labyrinth." Old guys and leather pants just don't work out. Eartha Kitt in leather pants, however...
Rowsdower**
Jan 12, 2004

Wait! I meant a YOUNG Eartha Kitt.
doggyxpus*
Apr 09, 2004

Doors don't talk. I've seen this teaser on the site before in a different form, hmmmm.....
metallicman*us*
Nov 12, 2005

How many letters are in my first name? Easy and simple question...
stephiesd**
Dec 30, 2005

i would have asked what color the sky was, or what day is it.
thompson1Aus*
Mar 14, 2006

I just thought of something! If you ask the Liars door, then they could just say "I don't know" and be lying because they really do know what the answer is.
I have definitely heard this before, but this is still a great teaser.
TehIgnored*us*
Mar 15, 2006

Yeah....this was from labyrinth...great film....I love David Bowie....but I could go without seeing him in skin tight stretch pants
rrn0rrnrrnY*us*
Sep 10, 2006

I have also heard in one form or another and don't care for this one. I also think there are many simpler questions for the door of liars to get to the truth door. Just my opinion.
elu93Aus*
Nov 21, 2006

weren't you just supposed to poke it with a stick and ask it if you just poked it? oh well,
slicktrumpetAus*
Apr 10, 2007

I don't quite understand the second answer... it's just not making sence to me.
udoboy*us*
Aug 10, 2007

If you only get to ask one question, and waste the question by asking the door the number of letters in your first name or some other unrelated question, you're stuck.
Bartman1
Nov 16, 2007

"Does this door lead to your home city?" If he says yes, it's the city of truth. If he says no, it's a lie.
javaguru*us*
Jan 07, 2009

How about "If I ask you a question, will the other door give me the same answer as you?" The lying door says yes, the truth door says no.

This avoids having to establish any external truth to test the doors against, yet is still just a question with a known answer.
brain23tus*
Jun 20, 2009

Ask, "What's my name?" If it doesn't tell you your name, pick the other door.
sashomarinetus*
Feb 19, 2010

I asked "am I only alowed one question?"
FrostyRej
May 14, 2014

Why don't we just ask them something that we know true?

That would be a lot easier lol.
And it's not even written against the rule. You're just complicating things.



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