Quote:
Originally Posted by balint-glm
I choose a goat initially, the guy helps me by removing one goat, I change, I win/I stay, I loose.
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No, you don't understand how it works. The guy really helps you by removing the empty value (he
initially knew it's empty). So he just redistributed the probability from a+b+c=100 to a+b=100. After that you have a 50% chance instead of 33.3(3)%. So mathematically you just have a set of new parameters (a new task).
Now surprise (opening you a secret of the magic)! If fact you had a 50% chance from the beginning. Because only 2 doors count (the one with the prize and one w/o it) because the 3rd door does not participate in the game. One of two
knowingly empty doors will be removed from the game by the host. It doesn't matter which exactly door did you choose, because the dude will remove the remained empty one anyways (there is always at least one room will be empty). So you start the game with 2 doors (not with 3) because the 3rd one was a fake butaphory. In fact you already have 50/50 chance and it doesn't matter will you change your mind or not.
Quote:
Originally Posted by balint-glm
I think the debate is closed with this video
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Of course not. Does the video explains that there is no 3rd door at all? Formally there are really 3 doors, but one empty door will be removed from the game right at the beginning and there will be only a door with a prize and one door which is empty. There are two doors are available for you initially. The 3rd one is a mirage (it's a fake). The game host tells you: choose one of 3 doors and I will remove one of the reminded ones which
knowingly has no prize inside, because I know it's empty, so you will stay will two doors: one with a prize and one w/o it (a 50/50 chance) Would you like to change the door? You may say: so why there where 3 doors initially? And you've get his answer: to confuse you, moron!
A stupid show for silly people. As about Monty Hall, so he was just a senile Alzheimer old man. I don't understand the people who still believe in Voodoo magic and can be tricked by a hocus-pocus which was worked before A.D...
P.S. As I said above, this "phenomena" has nothing to do with mathematics (everybody who has studied it in the school knows the chance is 50/50). It is a trick on human's psychology. A very simple trick which works on silly people only. Everybody who has a bit of logic will recognize the "catch" from the beginning. Some people think that women can't think logically. So yesterday I have shown that video to my wife and asked what she thinks. She answered right immediately: they are idiots, the chance is 50/50, because there is only 2 rooms - one with a prize and another one w/o it.
And she was right. Doesn't matter how many empty rooms there were before if all of them were excluded from the equation by the game host, because he has left only two and only one of them has a prize. You can change your mind a million times, but the chance will be 50% anyways.