[Brain Teaser] Three doors - page 2.

ndnh

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Quote from: (oYo) on April 03, 2015, 08:17:53 PM

1) Is there an advantage to choosing "No" or "It doesn't matter" in the poll?
2) Is there a 50/50 chance those answers both mean the same thing?
3) Is there no advantage, since there's 100% absolutely no difference in their meaning?

1) No advantage. Both are apparently wrong. Huh

2) They don't mean the same thing. No means you would NOT switch. It doesn't matter means, whether you switch or not it has got the same odds.
In other words: No applies whenever, odd of winning after not switching are more or equal to the other.
It doesn't matter, applies only when they are equal, i.e. 50/50

3) What advantage are you talking about? Both options are not mutually exclusive, but they certainly does not mean the same.

hedgy73

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Quote from: matt4054 on April 03, 2015, 08:34:38 PM

Quote from: (oYo) on April 03, 2015, 08:17:53 PM

1) Is there an advantage to choosing "No" or "It doesn't matter" in the poll?
2) Is there a 50/50 chance those answers both mean the same thing?
3) Is there no advantage, since there's 100% absolutely no difference in their meaning?

Having posted 3 questions above, is there a 0%, 33%, 50%, 66%, or 100% chance that one of them is a logical question? Cheesy

I find them very logical indeed, it's all about the law of excluded middle

I admit that there's an ambiguity in the formulation between something that is not to your advantage and something that is to your disadvantage.

Christ that's complex looking forward to the answer

hedgy73

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I'm sorry but I have no idea to the question but will stay tuned for an answer.

I'll go to bed thinking about this tonight....

matt4054

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Quote from: (oYo) on April 03, 2015, 08:17:53 PM

1) Is there an advantage to choosing "No" or "It doesn't matter" in the poll?
2) Is there a 50/50 chance those answers both mean the same thing?
3) Is there no advantage, since there's 100% absolutely no difference in their meaning?

Having posted 3 questions above, is there a 0%, 33%, 50%, 66%, or 100% chance that one of them is a logical question? Cheesy

I find them very logical indeed, it's all about the law of excluded middle

I admit that there's an ambiguity in the formulation between something that is not to your advantage and something that is to your disadvantage.

(oYo)

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1) Is there an advantage to choosing "No" or "It doesn't matter" in the poll?
2) Is there a 50/50 chance those answers both mean the same thing?
3) Is there no advantage, since there's 100% absolutely no difference in their meaning?

Having posted 3 questions above, is there a 0%, 33%, 50%, 66%, or 100% chance that one of them is a logical question? Cheesy

matt4054

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Quote from: hedgy73 on April 03, 2015, 07:42:44 PM

Ok thanks, then I'll say there should be no obvious explanation that there would be an advantage switching as it would be 50/50.

It's one of the most counterintuitive problem I've ever seen.

Some have already given elements of the answer. I will add the following hints:

The game master will always have to open 1 of the 2 doors that you didn't pick. Now you may want to know if he will always open a losing door or not (supposing you didn't pick the winning one in the first place). I will answer that opening the winning door would make the game over instantly, and the switch-or-not question irrelevant. As far as I'm concerned, the key to the explanation was grouping the 2 unpicked doors together when considering probabilities.

hedgy73

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Quote from: matt4054 on April 03, 2015, 07:14:26 PM

Quote from: hedgy73 on April 03, 2015, 06:32:13 PM

Does the game master have to give you the chance to change your mind? Does he want the contestant to win or lose?

Yes he does. His intention is unknown and should be irrelevant.

Ok thanks, then I'll say there should be no obvious explanation that there would be an advantage switching as it would be 50/50.

(oYo)

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My initial choice has a 33% chance of being right. (You could also say there's a 66% chance of choosing the wrong door.) That's a gimme, since there are initially 3 doors to choose from.

If one of the doors (which I didn't choose) is revealed to be a poor choice and subsequently removed from the equation, that leaves 2 doors to choose from, ergo there's a 50% chance now of choosing the right (or wrong) one. Since both of the remaining doors now have an equal chance of being the right (or better) choice, this also means that my odds of having already chosen the right door just shot up from 33% to 50%. Another way of looking at it is that my odds of choosing the wrong door went down from 66% to 50%. Hence there's absolutely no advantage (or disadvantage) to switching to the other door.

This 'brain teaser' feels somewhat like that joke where the three guys get a rebate on their hotel room and you are misdirected to account for a missing dollar.

matt4054

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Quote from: hedgy73 on April 03, 2015, 06:32:13 PM

Does the game master have to give you the chance to change your mind? Does he want the contestant to win or lose?

Yes he does. His intention is unknown and should be irrelevant.

hedgy73

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Quote from: matt4054 on April 02, 2015, 09:39:09 AM

If you already know about the original version of this problem please don't spoil the answer too soon, let's keep it fun, thanks

Suppose that you're given the choice of three closed doors. Behind one door is 1BTC, behind the others, 1 satoshi. You pick a door, say #1, but you can't open it yet. The game master, who knows what's behind the closed doors, opens another door, say #2, which has 1 satoshi.

Then the game master asks you whether you want to pick door #3 instead of door #1.

Is it to your advantage to switch your choice?

Does the game master have to give you the chance to change your mind? Does he want the contestant to win or lose?

9000

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This is a great example of a counter-intuitive solution, the vast majority of people answer that there is no difference.

ndnh

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Quote from: Bardman on April 03, 2015, 08:26:26 AM

Quote from: AltcoinInvestor on April 03, 2015, 08:07:02 AM

it's a 50/50 chance it really doesn't matter which one you choose.

Did you just come with that conclussion by yourself?? Seriously what kind of useless post is this? Switching the door gives you a 2/3 chance of winning not a 50% like did you even read the thread?

The question he answered was deleted.

Thanks

Bardman

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Quote from: AltcoinInvestor on April 03, 2015, 08:07:02 AM

it's a 50/50 chance it really doesn't matter which one you choose.

Did you just come with that conclussion by yourself?? Seriously what kind of useless post is this? Switching the door gives you a 2/3 chance of winning not a 50% like did you even read the thread?

AltcoinInvestor

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it's a 50/50 chance it really doesn't matter which one you choose.

ndnh

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Quote from: jmintuck on April 03, 2015, 04:07:59 AM

I read the explanation on wikipedia a while back. Still doesn't feel right, and I will never have an intuitive understanding of it I suppose.
I think of it like dice at times , and its like saying that select a range between 1 and 100, between 1-33,34-67,68-100(dont worry about the differnce of 1, just consider it 1/3) . Now you select 1-33. Dice site owner checks seed to tell you its not 68-100. Then how does switching to 34-67 increase odds ?

Or take it like this. Really simple to understand.

What is the chance that you miraculously picked the correct door? It is 1/3

What is the remaining chance? 1-1/3= 2/3 !

That is 1:2. You should switch.

Bardman

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Quote from: jmintuck on April 03, 2015, 04:07:59 AM

I read the explanation on wikipedia a while back. Still doesn't feel right, and I will never have an intuitive understanding of it I suppose.
I think of it like dice at times , and its like saying that select a range between 1 and 100, between 1-33,34-67,68-100(dont worry about the differnce of 1, just consider it 1/3) . Now you select 1-33. Dice site owner checks seed to tell you its not 68-100. Then how does switching to 34-67 increase odds ?

There is an example to make it easier: You have 3 doors, Red Yellow and Green.

In the case that the Bitcoin us behind the red door:
If you pick the red door switching would make you lose
If you pick the yellow door switching would make you win
If you pick the green door switching would make you win

Lose 1/3
Win 2/3

jmintuck

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I read the explanation on wikipedia a while back. Still doesn't feel right, and I will never have an intuitive understanding of it I suppose.
I think of it like dice at times , and its like saying that select a range between 1 and 100, between 1-33,34-67,68-100(dont worry about the differnce of 1, just consider it 1/3) . Now you select 1-33. Dice site owner checks seed to tell you its not 68-100. Then how does switching to 34-67 increase odds ?

ndnh

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Quote from: matt4054 on April 02, 2015, 08:34:47 PM

Well, I guess it's a bit too much of a classic for those willing to click on brain teasers... gg Grin

Quote from: ndnh on April 02, 2015, 03:52:19 PM

Were the funds escrowed? Was it a physical bitcoin?

Revenge for asking stupid questions..

Yes, rest assured, funds were escrowed by Monty Hall.

"Stupidity is a talent for misconception." -- Edgar Allan Poe

Was the transaction fee covered?? Shocked

"Stupidity is a talent." -- Sam Gamgee

\o/

Gleb Gamow

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I voted yes sans reading the first word in the OP, for I knew what this thread was about. I wasn't disappointed.

matt4054

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Well, I guess it's a bit too much of a classic for those willing to click on brain teasers... gg Grin

Quote from: ndnh on April 02, 2015, 03:52:19 PM

Were the funds escrowed? Was it a physical bitcoin?

Revenge for asking stupid questions..

Yes, rest assured, funds were escrowed by Monty Hall.

"Stupidity is a talent for misconception." -- Edgar Allan Poe

Topic: [Brain Teaser] Three doors - page 2. (Read 2338 times)