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closed envelope paradox - math guys wanted!!


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Okay...this thread may not be for everyone.If you're a math guy please assist if you can.Here's the scenario:- There are 3 closed envelopes that look identical.- One of these envelopes contain $1,000,000- The other two envelopes contain nothing- You will choose one of the three envelopesNow here's the question:Without opening the envelope to look inside...If you are given the choice of either keeping the envelope you have OR trading it for one of the other two which choice is better?My initial thoughts:This is a stupid question. It doesn't make a difference because everything is random anyhow. Your probability of picking the $1M winner is 33.3% regardless of choice. It's like a kid going..."I'll take envelope #1...wait, nono...I'll take #3!"...the chances are the same since you don't know what's inside the initial pick.Theorem from Mathematician:I don't know the details (and thus this post)...but it goes something like this but at a much more complex level.Let Pile A = Initially picked EnvelopeLet Pile B = Other 2 EnvelopesPile A has a 33.3% chance of having the $1MPile B has a 66.7% chance of having the $1MTherefore, there is a greater chance of the winner being in Pile B.By choosing to trade for a Pile B envelope you are getting a 50/50 scenario on picking the $1M from a more likely winning pile.Therefore it is always correct to choose to exchange your initial choice.Final thought:I have simplified the theorem and any guy that can even tackle this may flame the crap outta me for messing up the explanation.I've been told that it cannot be answered in a short manner such as the one I just made.To me...I quickly dismissed the theory I just posted because the 50/50 of Pile B in my mind is just 50% of 66.7% which is 33.3% anyhow...just like it was from the beginning.If you can give me a link or explaination for this it's greatly appreciated. My mind is working overtime trying to think of how there could actually be a big debate in the math world about this seemingly simple question.

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just pick the one thats heavier...hehe
You know, if I were to do this sort of thing, with the envelopes, I might just put a piece of paper in each one, and write on them:NOTHING1 MILLIONNOTHINGAnd then take care of things at the end. But...........that really has NOTHING to do with the OP.-Shawn K.
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you asked a different question than the one posted earlier. your question depends on not knowing what's in the first envelope you choose, while in the previous threads, your first choice is opened and shown to reveal a goat. the way you asked it, no, you are wrong. at first, there is a 1/3 chance you picked right and a 2/3 chance you picked wrong. if you decide to switch, you are gambling 50-50 that you will be right, but there's only a 2/3 chance the check is in either of the doors, so 50% of 2/3 is 1/3, the original probability. i'm still trying to work out what you should do if you can see one of the other doors, but i just blazed so that might not happen anytime soon, or ever. good luck

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Thanks for the post...very similar question on your links I suppose but it's kind of easier for me to see the other side in the 3-door example because more information has been given after opening one of the doors.In my example here you are never given additional info on any of the three envelopes. They are simply unknown the entire way.I feel like I'm searching for Will Hunting to get the proof.
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If there is no extra information that one of the other 2 envelopes does not contain the check, then it doesn't matter if you switch envelopes or not.

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If you can give me a link or explaination for this it's greatly appreciated. My mind is working overtime trying to think of how there could actually be a big debate in the math world about this seemingly simple question.
There isn't such a debate because what you described is nothing like the paradox in question.The Envelope Paradox is completely different, though interesting especially around these parts since it's all about EV...
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Thanks for the post...very similar question on your links I suppose but it's kind of easier for me to see the other side in the 3-door example because more information has been given after opening one of the doors.In my example here you are never given additional info on any of the three envelopes. They are simply unknown the entire way.I feel like I'm searching for Will Hunting to get the proof.
with no extra information, there is no proof, that's why its called a paradox. i usually assume that people alot smarter than me have tried and failed... then have a beer.
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This is so trivially easy. There is no paradox.Assuming all three envelopes are identical it doesn't matter which one you choose and trading doesn't help you because you could be trading away the one with the million.

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Like some have already said, you're confusing your paradoxes. The problem that you are trying to discuss is generally known as the Monty Hall Problem. Google it to find a ton of discussions, or check out some of the above links. The envelope paradox involves two envelopes, and is also a very interesting problem. But the way that you have stated it, there really is no paradox.

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If you can give me a link or explaination for this it's greatly appreciated. My mind is working overtime trying to think of how there could actually be a big debate in the math world about this seemingly simple question.
There isn't such a debate because what you described is nothing like the paradox in question.The Envelope Paradox is completely different, though interesting especially around these parts since it's all about EV...
Thank you. With no new information it doesn't matter if you switch.If Monty Hall's going to open a door, you switch.
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