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this makes no sense to me
Topic Started: Mon Mar 31, 2008 11:51 pm (256 Views)
Geofari
Level 13
you start out with 3 doors
behind them are 2 goats and a car
the car is placed randomly
a guy comes by and opens one door
its a goat
the car has not moved
you can change your choice between the 2 doors left
are your chances now 50/50 or 66/33?
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AsSaSsiN
Level 29
someone saw 21 over the weekend
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Geofari
Level 13
AsSaSsiN
Mar 31 2008, 11:06 PM
someone saw 21 over the weekend

i didnt
my friend was trying to explain it to me and i just cant understand how its possibly 66/33!!!!!!
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FaZ-
Level 39
33% chance if you don't change doors.
50% chance if you do.

Classic statistics problem that baffles many very intelligent people at first notice. It's known as the "Let's Make a Deal" problem to me. Thanks Monty Hall?
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MaKsU
Level 11
i remember this from 21 i dont really understand either <.<
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Sarge
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Hacker Hunter
The classic trick to this is that the problem usually involves 'you choose again', and they don't say between the 2 remaining doors. then the chance would still be 33/66 to get the car, technically.
If you throw in the words, 'between the 2 remaining doors', it becomes 50/50.
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TeaLaGe
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Level 50
hmm, let me try to explain.

You choose door 1. The host would have to choose either door 2 or 3. that would reveal one of the goats. That would mean there is a 50/50 chance that you would get the car. The game host then says would u either stick with your choice or change it. Assuming that

A. you dont change your answer, and you stick with it. it would be d133/d266 because he doesnt says that it's whether to choose to choose between "the two doors" It's like he's trying to get you to change your answer..

door 1 = 33% door 2 = 66% but really it's actually 66/33

// so if u sticked with your answer you would get the car.. oh btw. they cant switch it. That would be absurd to move the car and the goats around.

B. You change your answer and you choose D2. That would mean that you believe it's going to be in D2 but really it's d1-66%/d2-33% so you don't get the car.

----------------

now unless the game host manage to be able to move the cars and goats around.....

If You choose door 2 - the gamehost would have to show one of the goats.
That would mean the game host would have to choose one of the doors leading to a goat, assuming he chooses door 3, and there's a goat in it, the game host would try to deceive you by saying "would you like to stick with your answer or change it" then it could be d133/d266.

Whatever some bullshit. idk, i probably got it wrong but it was fun. i know how to figure it out but cant explain :/


-----------------

"you start out with 3 doors
behind them are 2 goats and a car
the car is placed randomly
a guy comes by and opens one door
its a goat
the car has not moved
you can change your choice between the 2 doors left
are your chances now 50/50 or 66/33?"

-----------------

Ah.. now i see, you havent picked a door yet. You gotta pick a door and stick with it and wait till the gamehost choose which door to deceive you with, then the whole equation works.

---

The game host chooses door 3. since "2 doors left" that would mean you choosed door 1. yes 66/33 is correct. Bullshit gamehost.

to sum it all up..

A. Host choose door 3.

B. You choose door 1

C. He says 66/33 or 50/50

D. You stick with it because he's the gamehost who wont let you win the damn prize.

E. D166 D233.

F. If there are more then one doors.. or the goats and cars move around..then hard..

--------------------

There are many variations of this crap, are you sure you arent missing out any details?
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AsSaSsiN
Level 29
.. lol (in the movie this is what happens)

Guy picks door one, and host says number 3's a goat, he then asks if he would like to switch his pick to door #2 the guy says yes because now his odd's are 66/33 if he picks door 2, so he picks door 2 and wins the car.
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Gam3dbz
Level 7
isnt the question why its 66% and not 50%?
thanks for clarifying the situation though
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TeaLaGe
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Level 50
the only explanation i got is

The show host doesnt want the player to get the car.
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Geofari
Level 13
TeaLaGe
Apr 1 2008, 11:20 PM
the only explanation i got is

The show host doesnt want the player to get the car.

i would add on that its a psychological thing
the contestant would doubt his/her choice after one is revealed incorrect
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Lintendo
Level 5
Lets assume that door A is the winning door, looking at all possible scenarios first we'll look at if we don't change our answers.

Pick Door A, Host opens B or C doesn't matter which, You keep your door you Win.
Pick Door B, Host opens C, You keep your door, you Lose
Pick Door C, Host opens B, you keep the door, you Lose.

So there u have a 33% of winning on not changing doors. Now we look at what happens if u change your answer each time

Pick Door A, Host opens B or C, You change doors, you Lose
Pick Door B, Host opens C, you change doors, you Win
Pick Door C, Host opens B, you change doors, you Win

now u have a 66% chance if u go for the door you didn't pick in the beggining. Hope that helps
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TeaLaGe
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Level 50
oh boy. u got all the answers from wikipedia. cheater.
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Hanabito
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Level 26
nice sig tealage lol
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TeaLaGe
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Level 50
ownt u hard.
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Lintendo
Level 5
haha no ididn't, i wrote that wikipedia page! haah jk, but relaly, ididn't get it from wikipedia, u just think of all the possible answers and tahts what u get
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Hanabito
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Level 26
i spammed out so hard he quit forums
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TeaLaGe
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Level 50
lol
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DeMaGoG
Level 23
Darn Lintendo, you beat me to the explanation :(
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