jfalk
jfalk
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January 28th, 2011 at 6:42:33 AM permalink
You have committed a hanging offense in a small, but highly logical, town. You are convicted and sentenced on Friday. The Judge pronounces the date of your execution: "You will be hanged one day next week: Monday through Friday. In order to make you suffer a bit more, I guarantee you will not be able to deduce the day of your execution the day before." "Great," you respond, "then I'm free. I can't be executed on Friday, because then I would know it on Thursday. But that means I can't be executed on Thursday, because on Wednesday I'd know it would have to be Thursday since it can't be Friday. But if it can't be Thursday, it can't be Wednesday, and if it can't be Wednesday it can't be Tuesday. But that means it can't be Monday either. That exhausts the possibilities, so you cannot execute me next week."

What, if anything, is wrong with this reasoning?
AZDuffman
AZDuffman
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January 28th, 2011 at 6:45:28 AM permalink
Quote: jfalk

You have committed a hanging offense in a small, but highly logical, town. You are convicted and sentenced on Friday. The Judge pronounces the date of your execution: "You will be hanged one day next week: Monday through Friday. In order to make you suffer a bit more, I guarantee you will not be able to deduce the day of your execution the day before." "Great," you respond, "then I'm free." I can't be executed on Friday, because then I would know it on Thursday. But that means I can't be executed on Thursday, because on Wednesday I'd know it would have to be Thursday since it can't be Friday. But if it can't be Thursday, it can't be Wednesday, and if it can't be Wednesday it can't be Tuesday. But that means it can't be Monday either. That exhausts the possibilities, so you cannot execute me next week."

What, if anything, is wrong with this reasoning?



Hanging is no longer a permissible means of execution?
Tolerance is the virtue of believing in nothing
Mosca
Mosca
Joined: Dec 14, 2009
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January 28th, 2011 at 6:57:24 AM permalink
You're gonna get hanged on Monday.
NO KILL I
DJTeddyBear
DJTeddyBear
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January 28th, 2011 at 7:37:26 AM permalink
Quote: Mosca

You're gonna get hanged on Monday.

.... And you know it today - THREE days beforehand.

The probolem is, there is nothing prolonged about the suffering.
Superstitions are silly, childish, irrational rituals, born out of fear of the unknown. But how much does it cost to knock on wood? 😁 Note that the same could be said for Religion. I.E. Religion is nothing more than organized superstition. 🤗
dwheatley
dwheatley
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January 28th, 2011 at 7:38:19 AM permalink
Or Tuesday. Either way, you can't know when you will get executed early in the week, so you will certainly be surprised (and thus cannot deduce the exact day). There's a PG version of this question using a pop quiz.
Wisdom is the quality that keeps you out of situations where you would otherwise need it
gog
gog
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January 28th, 2011 at 7:51:34 AM permalink
on thursday you can't tell if you're being hanged friday, or 11:59pm same day
odiousgambit
odiousgambit
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January 28th, 2011 at 8:05:32 AM permalink
I'm thinking Friday is the only day it can't be.
the next time Dame Fortune toys with your heart, your soul and your wallet, raise your glass and praise her thus: “Thanks for nothing, you cold-hearted, evil, damnable, nefarious, low-life, malicious monster from Hell!” She is, after all, stone deaf. ... Arnold Snyder
DJTeddyBear
DJTeddyBear
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January 28th, 2011 at 8:07:57 AM permalink
Quote: jfalk

I guarantee you will not be able to deduce the day of your execution the day before.


I'm changing my answer.


You'll be hanged Thursday afternoon.

The problem does NOT say that you WILL figure it out the day before, just that the day before, you still won't know.

Therefore, on Thursday, it could still be that day or the next day, but the longer the day goes on, the higher the likelihood that you'll figure it's gonna be Friday.
Superstitions are silly, childish, irrational rituals, born out of fear of the unknown. But how much does it cost to knock on wood? 😁 Note that the same could be said for Religion. I.E. Religion is nothing more than organized superstition. 🤗
jfalk
jfalk
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January 28th, 2011 at 8:47:10 AM permalink
OK then. If you're so sure you'll be hanged Thursday afternoon, then you've managed to deduce it on the Friday before! So it's no surprise.
MathExtremist
MathExtremist
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January 28th, 2011 at 10:39:10 AM permalink
Quote: jfalk

In order to make you suffer a bit more, I guarantee you will not be able to deduce the day of your execution the day before." "Great," you respond, "then I'm free. I can't be executed on Friday, because then I would know it on Thursday. But that means I can't be executed on Thursday, because on Wednesday I'd know it would have to be Thursday since it can't be Friday. But if it can't be Thursday, it can't be Wednesday, and if it can't be Wednesday it can't be Tuesday. But that means it can't be Monday either. That exhausts the possibilities, so you cannot execute me next week."

What, if anything, is wrong with this reasoning?



It assumes the Judge is correct. That's not necessarily true, especially if his intent is to cause suffering. As a result, it's entirely possible for the you to be hung on Friday. On Friday, you can exult in the knowledge that the Judge was wrong about your powerful deductive abilities ... as the hangman slips the noose over your head.
"In my own case, when it seemed to me after a long illness that death was close at hand, I found no little solace in playing constantly at dice." -- Girolamo Cardano, 1563

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