Truth teller vs liar : go to Hell

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SUMMARY

The discussion centers on a classic logical puzzle involving two guards, one who always tells the truth and one who always lies, guarding two doors: one leading to Heaven and the other to Hell. Participants propose various questions to determine which door leads to Heaven, with the most effective solution being to ask either guard, "What would the other guard say if I asked him which door leads to Heaven?" The answer given will always point to the door leading to Hell, allowing the questioner to choose the opposite door. This puzzle highlights the intricacies of logic and reasoning in problem-solving.

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  • Understanding of logical reasoning and paradoxes
  • Familiarity with basic question formulation techniques
  • Knowledge of truth-tellers and liars in logical puzzles
  • Ability to analyze and interpret logical statements
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  • Research "logical paradoxes" to explore similar puzzles
  • Learn about "truth-teller and liar" scenarios in logic
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Logicians, puzzle enthusiasts, educators teaching critical thinking, and anyone interested in enhancing their logical reasoning skills.

  • #31
How about .. "What door are you standing in front of?" The honest guard points to his door, and the liar guard points to the other one.
 
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  • #32
nuby said:
How about .. "What door are you standing in front of?" The honest guard points to his door, and the liar guard points to the other one.

Ok, now you know who the honest guard is.
And so what?

C'mon guys, you should read the first post.
 
  • #33
Rogerio said:
C'mon guys, you should read the first post.

It confused me, as I've heard it before but proposed differently: truth teller guards Heaven, lier guards Hell.

The no correlation between lying ang telling the truth and which door one is guarding does make a lot more sense now I've thought about it, as there is only one answer:

Will the other guard say he is guarding Heaven?

right?

Isn't this in Labyrinth with David Bowie?
 
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  • #34
neu said:
...
right?

Right.
 
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  • #35
kill both guards then open both doors but don't go in until you find out which door is the one you wish to go in (note some people want to go to hell like satanists)
 
  • #36
Would he say that you are lying?
 
  • #37
you ask either guards:
if i ask the other guard which door leads to freedom what door would he say?
they will show you the same door. you go to the other door.
the point is that the liar will point to the door of the tiger and so would the truth teller.
 
  • #38


Sorry to be totally dead-pan about this.
The answer is a Double Negative.
If you ask the Truthful man what the other man will say he will say what the Liar would say.
If you ask the Liar what the Truthful man would say he will say a Lie, ie the opposite of the Truthful man.
The question therefore is: "If I ask the other man what is the gate/door to life/freedom, what will he tell me" - whatever the answer you do the opposite, because both men will tell either a Lie or a Truthful Lie.
The question must be a Double Negative !
 

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