Impeccable logic
- Thread starter Kes
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The words Kettle and Black spring to mind Joe.
If you believe you know the probability, and can explain your working, then please go ahead, but at the moment you seem to be implying that the answer can't be computed, so I'm content to believe that I know the answer and that you don't.joe-90 said:Softus. Random chance doesn't have memory or favour one box over another. Any box could be the box on the table. Substituting any other box won't change that basic principle. Random chance is - well - random.
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FFSThat's the wrong answer.joe-90 said:
Hmm.
For anyone with an open enough mind to consider the problem in a simpler (but equivalent) form, if you've never heard of the "Monty Hall" puzzle then take a look at this site:
http://math.ucsd.edu/~crypto/Monty/monty.html
In the Monty Hall discussions it is said that if Monty doesn't know where the prize is then the switching odds are 50/50.
But in the cases where Monty guesses and choses an empty box the odds are still 2/3 in favour of switching. (You have to play to the first amendment of the game, that if Monty choses the prize then the game is null.)
The odds on the contestant picking the prize are 3/1. The odds of it being on Monty's side are 2/3. If Monty shows an empty box by accident or design it's still 2/3 that the prize is on his side. So switch.
No?
But in the cases where Monty guesses and choses an empty box the odds are still 2/3 in favour of switching. (You have to play to the first amendment of the game, that if Monty choses the prize then the game is null.)
The odds on the contestant picking the prize are 3/1. The odds of it being on Monty's side are 2/3. If Monty shows an empty box by accident or design it's still 2/3 that the prize is on his side. So switch.
No?
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Load of piffle.
You start with 22 boxes. The contestant picks one and puts it on the table. Then by random selection whittles down the boxes until there are just 2 left. One on the table and one on the counter somewhere. Switching those boxes around doesn't change anything. Whatever is in those boxes is in those boxes. It may be 50p or £250K or £100 or £20K. It makes no difference, it's simply random chance and nothing more.
You start with 22 boxes. The contestant picks one and puts it on the table. Then by random selection whittles down the boxes until there are just 2 left. One on the table and one on the counter somewhere. Switching those boxes around doesn't change anything. Whatever is in those boxes is in those boxes. It may be 50p or £250K or £100 or £20K. It makes no difference, it's simply random chance and nothing more.
so you agree then that this is not the monty hall thing..
since there is neither knowledge of what is in each box, and the player has the choice of 2 boxes then the chance of it being in either box is 50/50..
since there is neither knowledge of what is in each box, and the player has the choice of 2 boxes then the chance of it being in either box is 50/50..
I
imamartian
Kes, was the idea of the OP to resurrect the Monty Hall paradox, or were you genuinly posing the question with regards to Deal or no deal?
If it was the MH thing then enough time in the cosmos has been spent on this issue, search the 'net for that.... if it's a DonD question then it can only be 50:50....
When working with probability, you have to be quite precise about what you aim to prove... some people have mixed up the probabilties of all boxes, and dimishing probabilities etc. But in the OP it's mentioned that "and by a combination of blind chance and good fortune, whittle the lot down to two boxes, yours and one out there. The boxes have in them £250,000 and £1." Nothing that has gone before affects what is in either box... toss a coin and pick a box.
If it was the MH thing then enough time in the cosmos has been spent on this issue, search the 'net for that.... if it's a DonD question then it can only be 50:50....
When working with probability, you have to be quite precise about what you aim to prove... some people have mixed up the probabilties of all boxes, and dimishing probabilities etc. But in the OP it's mentioned that "and by a combination of blind chance and good fortune, whittle the lot down to two boxes, yours and one out there. The boxes have in them £250,000 and £1." Nothing that has gone before affects what is in either box... toss a coin and pick a box.
No - the OP states very clearly that "The boxes have in them £250,000 and £1".joe-90 said:
There's little point in repeating your assertion without an explanation of your working, or at least a rational explanation of where you think mine is wrong. As an explanation, "piffle" just doesn't cut it.
That's the trap that most people fall into.imamartian said:
However, if you repeat the scenario enough times to show the trend, then the probability becomes clear, even to the most hardened and closed-minded sceptics.
I
imamartian
Softus, what 'trap' have we fallen into? the OP states (as you keep mentioning), that there are two boxes.. one with £250k and one with a £1. Given that info only... 50:50 is the only conclusion unless you elaborate and explain what details we've missed.
The one of thinking that the original scenario (of there being 20 boxes) doesn't have a bearing on the moment at which you choose whether or not to swap.imamartian said:
Please show me where I "keep mentioning" it.
Please bear in mind that it isn't my responsibility to explain the correct answer to people who don't want to understand it. If you're happy to believe that it's 50:50, then go right ahead and believe it.
However, I've already elaborated, and I've supplied a link to one of many web sites that provides an explanation, so you merely have to read what's gone before and ask questions about that, not keep repeating that 'it has to be 50:50' as if you've got only one eye half open and only one brain cell in use.
I
imamartian
softus please clear up one issue... your links and your arguments seem to be focused on the MH paradox.... the OP and DonD is not about that...
as for there being 20 boxes before.... how does that affect the final question? what if there were 119 boxes? or 573 boxes beforehand? ..... mathematicians would have a field day with that one.... factorial 20 plus the date, minus Noels fee over the square root of the contestants age.. there are two boxes left with X and Y in.. pick one!
i accept that you dont keep mentioning the OP... rather it was mentioned in the previous post...
And i agree you have no responsibility to explain anything, but if thats true then how do we ever understand your arguement?
Let's take a huge raincheck on this thread and rather than arguing about the answer.... lets understand the question....are we talking MH or DonD?[/b]
as for there being 20 boxes before.... how does that affect the final question? what if there were 119 boxes? or 573 boxes beforehand? ..... mathematicians would have a field day with that one.... factorial 20 plus the date, minus Noels fee over the square root of the contestants age.. there are two boxes left with X and Y in.. pick one!
i accept that you dont keep mentioning the OP... rather it was mentioned in the previous post...
And i agree you have no responsibility to explain anything, but if thats true then how do we ever understand your arguement?
Let's take a huge raincheck on this thread and rather than arguing about the answer.... lets understand the question....are we talking MH or DonD?[/b]
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