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The Prisoners’ Paradox

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Re: The Prisoners’ Paradox

#21
post #12

Earlier quoted context omitted.

But, did he discovered new information? What if the guard had said "Prisioner C is sure to die"?

He did discover new information. The probabilities of survival switched from: A: 1/3, B: 1/3, C:1/3 to A: 1/3, B:0, C: 2/3 He just didn't discover any information to change the probability of his own survival.

[deleted]

Re: The Prisoners’ Paradox

#22

Earlier quoted context omitted.

Yeah, except it's pretty obvious why there is a switch to 1/2 from 1/3 in Prisoner's Paradox and it's not obvious in MH. What I understand happened in Prisoner's Paradox is that the very field of probabilistic distribution of pardons has shrinked from 3 to 2. It's like binary search. You cheated your way by knowing where _not to look_. Another simple analogy: you can increase the value of rational number both by incr…

You mean it's pretty obvious why there is no switch to 1/2 from 1/3? As the Wikipedia article you linked points out: "The answer is he didn't gain information about his own fate, but he should switch with C if he can." This isn't the same as Monty Hall. Monty Hall only increases the odds after switching doors. This actually seems like a trick meant to fool people who know about the Monty Hall problem but don't really…

It's strange why my blatantly stupid post was upvoted.

I re-read all three problems after you replied and this is what I understood. Talking about Three Prisoners' problem since the article's wording doesn't include the very crucial ingredient for easier understanding: coin flip on warden's side.

For A, it doesn't really matter if B or C were executed. In fact, he knew that either B or C are going to be executed for sure. He knew that at least one person who is not him will be executed.

Warden just named the sure-to-be-executed-guy. Didn't change what he previously knew about his chances, since he still doesn't know for sure whether the-other-not-named-guy is going to be executed.

However, the distribution changed for C. Now A still knows that there 1/3 chance of him living but since we know for sure that the-guy-who-warden-named (B or C) will be killed the-guy-who-warden-didn't-name-and-who-isn't-A (C or B) will have 1 - 1/3 = 2/3 probability of living.

Re: The Prisoners’ Paradox

#23
Forgive me, but doesn't it seem odd that the problem defines Prisoner A from one perspective, and Prisoner B from another?

Prisoner B could just as well be Prisoner A since A was defined by the narrator, and Prisoner B by the guard. I know we're descending into the theoretical stuff, probabilities and so on, but might there not even be enough information to go down any path at all given this dilemma?

Re: The Prisoners’ Paradox

#24
post #23

Forgive me, but doesn't it seem odd that the problem defines Prisoner A from one perspective, and Prisoner B from another? Prisoner B could just as well be Prisoner A since A was defined by the narrator, and Prisoner B by the guard. I know we're descending into the theoretical stuff, probabilities and so on, but might there not even be enough information to go down any path at all given this dilemma?

Prisoner A is the one that asks. That sets the one an only perspective for the guards answer.

Re: The Prisoners’ Paradox

#25

Earlier quoted context omitted.

You mean it's pretty obvious why there is no switch to 1/2 from 1/3? As the Wikipedia article you linked points out: "The answer is he didn't gain information about his own fate, but he should switch with C if he can." This isn't the same as Monty Hall. Monty Hall only increases the odds after switching doors. This actually seems like a trick meant to fool people who know about the Monty Hall problem but don't really…

It's strange why my blatantly stupid post was upvoted. I re-read all three problems after you replied and this is what I understood. Talking about Three Prisoners' problem since the article's wording doesn't include the very crucial ingredient for easier understanding: coin flip on warden's side. For A, it doesn't really matter if B or C were executed. In fact, he knew that either B or C are going to be executed for…

Correct.

Re: The Prisoners’ Paradox

#26
post #24
post #23

Forgive me, but doesn't it seem odd that the problem defines Prisoner A from one perspective, and Prisoner B from another? Prisoner B could just as well be Prisoner A since A was defined by the narrator, and Prisoner B by the guard. I know we're descending into the theoretical stuff, probabilities and so on, but might there not even be enough information to go down any path at all given this dilemma?

Prisoner A is the one that asks. That sets the one an only perspective for the guards answer.

Really? From whose perspective is Prisoner A described as asking the question? The narrator's. Please correct me if I'm wrong, but there is an implicit third person in my view.
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