Test your logic

Started by: ßub | Replies: 50 | Views: 2,599

Cereal Man
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Mar 22, 2008 3:40 AM #97572
Uh, what if you picked the car the first time?
ßub
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Mar 22, 2008 3:40 AM #97573
Quote from Exilement
lol wut


Quote from BloodFruit
lol wut.

shuddap. im dumb.
Schwa
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Mar 22, 2008 3:41 AM #97574
Quote from muttonhead
shuddap. im dumb.


lol wut.
Exile
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Mar 22, 2008 3:45 AM #97576
Quote from Cereal Man
Uh, what if you picked the car the first time?


Congratulations, you had a 1/3 chance of doing that.

You have a 2/3 chance of picking one of the goats.

That means switching every time will get you the car 2/3 times, while staying gets you it 1/3 of the time.

So if you picked it the first time, you're pretty much screwed, because mathematically you should switch, every time.
Sawc
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Mar 22, 2008 4:08 AM #97586
What? No. Just no. After he opens one door to show 1 goat, it's no longer a chance out of three, it's out of two. Get it? Got it? After one goat is eliminated, and you are choosing between door a and door b, there is NO door c. Therefore, it's a 50/50 chance at the last. Before the revealing of one goat and after are two seperate problems, not one.
ßub
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Mar 22, 2008 4:28 AM #97603
Quote from Sawc
What? No. Just no. After he opens one door to show 1 goat, it's no longer a chance out of three, it's out of two. Get it? Got it? After one goat is eliminated, and you are choosing between door a and door b, there is NO door c. Therefore, it's a 50/50 chance at the last. Before the revealing of one goat and after are two seperate problems, not one.

That is what most people think. However you are wrong. Your peanut sized brain apparently cannot comprehend the riddle.
Exile
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Mar 22, 2008 4:29 AM #97607
You can ignore the 3rd door, yes, but you can't ignore your first choice.

In the simplest form of this problem, you can assume this: if you pick the car, switching gets you a goat. if you pick one of the 2 goats, switching gets you the car.

Remember this:

Options (Switching)

Pick the car first, switch, you lose

Pick goat A first, switch, you win

Pick goat B first, switch, you win

Options (Staying)

Pick the car first, stay, you win

Pick goat A first, switch, you lose

Pick goat B first, switch, you lose



6 outcomes, that means each outcome has a 1 in 6 chance of occuring. There are 3 that cause you to win, and 3 that cause you to lose. You could say that this would constitute a 50/50 chance of winning, since 3/6 outcomes will cause you to win.

However, you only have 2 options (switch or stay). That means each option gives you 3 possible outcomes. 3 allow you to win, 3 allow you to lose. That means there are only two possible ways to divide those 6 outcomes between the 2 options:

One option has 3 possible chances to win, the other has 3 possible chances to lose.

OR

One option has 2 possible chances to win and 1 to lose, and the other has 1 possible chance to win and 2 to lose.

The first situation would be the only possibility for this to give you a 50/50 chance. However, that's simply a hypothetical. It's not how the problem goes at all.

There's no possible way for this to be reduced to a 50/50 chance, and there's no possible way for me to explain it any further.
Jeremy
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Mar 22, 2008 4:30 AM #97609
Quote from muttonhead
Your peanut sized brain


Irony .
Exile
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Mar 22, 2008 4:34 AM #97610
This also might help:

Image
Vervanda

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Mar 22, 2008 4:40 AM #97611
still dont grasp the concept
ßub
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Mar 22, 2008 6:20 PM #97983
Geez Exilement, you're doing a lot of work.
Eccentrix
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Mar 22, 2008 10:45 PM #98159
I'd rather ride the goat
Schwa
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Mar 22, 2008 10:52 PM #98162
Quote from Eccentrix
I'd rather ride the goat


Are you thinking what I think you're thinking? *wink wink nudge nudge*
Eccentrix
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Mar 23, 2008 2:55 PM #98766
idk *wink wink nudge nudge*
Scarecrow
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Mar 24, 2008 12:59 AM #99414
I remember seeing a newspaper article about this a while back. I'll see what I can find.

*edit*

Proof of 2/3:

http://en.wikipedia.org/wiki/Monty_hall_problem