You are on TV show,
there are 3 doors,
behind 2 of them there is a goat,
behind one is new BMW

you opened the door and the host opens another door to show you it has a goat behind it. The host offers you to change your mind and pick up the other unopened door.

Question:
do you have
1) better chances by opening the other door?
2) worse chances by opening the other door
3) the same chances by opening the other door?

...and why?

there are two answers to this problem.

ifit is a trick question, the fact that you said "a goat" would imply one goat, which if already revealed would mean your options are better. but if there was a goat behind the door you opened (not specified) then your odds would be 100% that the third door would hold a BMW, since both goats would be revealed.

so that argument is all semantics.

Say the door you opened was goatless, then it comes down to odds.

the mathematical approach is you started with 66% odds of failure to start. eliminating one goat would mean your odds drop to 50% of failure, or a coin flip.

at least thats my take

gotta be my bad English...

there are goats behind 2 out of 3 doors

you haven't opened the door,
you only indicated the door which you would like to open.

sorry for misunderstanding the first time around

bzzz...wrong!

oh shit i missed it completely.... one sec.

there is nothing specifying that a goat cannot be behind the same door as a goat.

so the odds of failure are 5/6 for the goat with the BMW and 1/3 with the goat and BMW separate. so its a combination of odds problem

now the host eliminates one out of each... since obviously the goat would not be in the door he opened, or the contetant would have already won. and the same goes for the door the contestant opened. so there is one door left with 3 possibilities. a goat, a BMW, or a goat and a BMWso it is 1/3 or 33%,much better odds.



fucking trick questions

goat cannot be behind the same door as another goat, or the BMW, but that doest change the outcome. the revealing of the goat took us to 1/3 anyway, if and only if there were two goats in there, her odds would go to 100% choice as she had seen both goats and an empty door, so that doesnt matter.

anyway her odds are better

You have an equal chance by opting to open the other door.

You have a 66% chance of picking a goat on the first choice, the host then opens a door revealing a goat, cutting that down to a 66% chance of one of the doors containing a goat which, in actuality turns out to be a 50% chance you either have the goat or the BMW.

Grimm,
I'll make it VERY simple:

door #1 has goat behind it,
door #2 has goat behind it,
door #3 has BMW behind it.
THIS you know.
What you don't know is:
which door is which.

and you did NOT open the door on the first try,
you only indicated which door you want to be opened,
IOW,
you don't know what's behind the door you have chosen!

You have an equal chance by opting to open the other door.

You have a 66% chance of picking a goat on the first choice, the host then opens a door revealing a goat, cutting that down to a 66% chance of one of the doors containing a goat which, in actuality turns out to be a 50% chance you either have the goat or the BMW. [/b][/quote]
you missed the possibility of two goats being behind any door, nor the combinations of goat +BMW, or goat + goat + BMW

you missed the possibility of two goats being behind any door, nor the combinations of goat +BMW, or goat + goat + BMW [/b][/quote]
Thats true however that wasnt how i read the questions meaning ;)

Plus, we already know that behnd the door the host opened is 1 goat ;)

and its all moot if the door the contestant opens contains a BMW;)

You have an equal chance by opting to open the other door.

You have a 66% chance of picking a goat on the first choice, the host then opens a door revealing a goat, cutting that down to a 66% chance of one of the doors containing a goat which, in actuality turns out to be a 50% chance you either have the goat or the BMW. [/b][/quote]
Lee,
you haven't answered my question which was:
Question:
do you have
1) better chances by opening the other door?
2) worse chances by opening the other door?
3) the same chances by opening the other door?


even though you answered the _why_ question
(incorrectly, I might say)
;-)))

grimm,
pay fucking attention,
contestant doesn't open shit!
he only INDICATES what he wants to be opened.

Sorry thought i said you had an equal chance by opening the other door.

There are only 2 doors left, one of them contains a car.. the other doesnt ;)

Thats true however that wasnt how i read the questions meaning ;)

Plus, we already know that behnd the door the host opened is 1 goat ;) [/b][/quote]
Lee,
you missed nothing,
it's grimm wjho misses everything
;-))

..even though BOTH of you gave incorrect answers.
;-)))

Actually you know what..

Thinking about it logically..

No matter what door you open you have a better chance..

Youll either win a car or not.. which is more than you have right now prior to the door being opened :)

Now what do i win? LOL

you did, but
#3, the answer you gave, is INCORRECT answer
;-))))

Well shit you could have broken it to me easier than that ;)

you win NADA, zilch, fat ZERO....

all you have to do to win is to pick up the correct answer from
and give the reasoning WHY
;-)
you now have only 2! correct answers left to chose from
;-)))

oh ok, so she did not open the door, just indicated.

this is boolean algebra.

1 goat

1 BMW

2 Doors

initially she had a 1/3 shot. 66% rate of failure.

doh this is easy

her shot remains the same. nothing has changed. She still has 3 doors, two goats, one behind each door. and a BMW behind the third. so instead of it being a 66% rate of failure by remaining the same. so she keeps her pick, er odds of failure reduce to 50%. 1/2 instead of 1/3. all the host did was show 1/3 of her failure options.\

is that correct?

oh ok, so she did not open the door, just indicated.

this is boolean algebra.

1 goat

1 BMW

2 Doors

initially she had a 1/3 shot. 66% rate of failure.

doh this is easy

her shot remains the same. nothing has changed. She still has 3 doors, two goats, one behind each door. and a BMW behind the third. so instead of it being a 66% rate of failure by remaining the same. so she keeps her pick, er odds of failure reduce to 50%. 1/2 instead of 1/3. all the host did was show 1/3 of her failure options.\

is that correct? [/b][/quote]
Thats what i said didnt i? LOL

oh ok, so she did not open the door, just indicated.

this is boolean algebra.

1 goat

1 BMW

2 Doors

initially she had a 1/3 shot. 66% rate of failure.

doh this is easy

her shot remains the same. nothing has changed. She still has 3 doors, two goats, one behind each door. and a BMW behind the third. so instead of it being a 66% rate of failure by remaining the same. so she keeps her pick, er odds of failure reduce to 50%. 1/2 instead of 1/3. all the host did was show 1/3 of her failure options.\

is that correct? [/b][/quote]
grimm,
your logic is correct, but it doesn't give the answer to my question which was:
which answer you think is correct, knowing from me that #3 is INCORRECT answer?

shit someone beat me to it, but i explained my reasoning;)

when i get logic problems, i always shoot fr the simplest answer. if i cannot find a simple answer, my analytical side kicks in and i narrow it down to the simplest answer. this whole board was lucky i wasnt boiling it down to the LCD of every possibility:)

Thats what i said didnt i? LOL [/b][/quote]
you did, but...I am looking for simple answer:
1)
2)
or
3)

and I can assure you,
3) is INCORRECT.

grimm,
your logic is correct, but it doesn't give the answer to my question which was:
which answer you think is correct, knowing from me that #3 is INCORRECT answer? [/b][/quote]
oh better odds

66% rate of failure> 50%


so 1.

yes, you BOTH beat each other to..INCORRECT CONCLUSION
;-))))

yes i overthunk it:)

and overcomplicated it:)

oh better odds

66% rate of failure> 50%


so 1. [/b][/quote]
BINGO!
we have a winner in WHICH possibility,
even though the answer to WHY is INCORRECT,
it doesn't support the 1) answer...
;-))

by your logic,
chosing new door or remain with your original choice gives the SAME 50-5- chance and this is WRONG conclusion and doesn't justify the opening of another door.

serge, my first answer was sorta right, read the second paragraph if this was a logic not a trick question:)

so technically, i got it right the first time, then outhtought myself into the wrong answer by overcomplicating it, then thought back to the right answer

:)))))

anybody cares to come up with plausable explanation WHY it's ALWAYS pays to chose the other door, after the host opened one of them?

Haha i did the same thing Grimm went from 66%-50% but was concentrating on the wrong thing lol

Ah well it was a stupid question anyway and neither of won a new BMW or a goat ;)

serge, my first answer was sorta right, read the second paragraph if this was a logic not a trick question:)

so technically, i got it right the first time, then outhtought myself into the wrong answer by overcomplicating it, then thought back to the right answer

:))))) [/b][/quote]
grimm,
your answer AND logic was incorrect and STILL is incorrect, because your chances of picking up the car by switching your original decission is NOT 50%...
it's 66%!!! probability to pick the car instead of goat when you switch!
;-))))

BINGO!
we have a winner in WHICH possibility,
even though the answer to WHY is INCORRECT,
it doesn't support the 1) answer...
;-))

by your logic,
chosing new door or remain with your original choice gives the SAME 50-5- chance and this is WRONG conclusion and doesn't justify the opening of another door. [/b][/quote]
true. duh. jeez.


but 1 and 3 would be the same. so eithr answer is right.

how is one any less right than 3 if the end result is the same?

very simple,
as I posted in my previous post,
the chances of winni9ng the car by switching your original choice is 66%,
not 50!!!!!!!!!!!!!!!!!

grimm,
your answer AND logic was incorrect and STILL is incorrect, because your chances of picking up the car by switching your original decission is NOT 50%...
it's 66%!!! probability to pick the car instead of goat when you switch!
;-)))) [/b][/quote]
Okay how do you figure that out?

If there are 3 doors and one has already been opened you wont choose that door.

1 goat
1 car

2 doors

50% chance of picking the right one when i went to school :huh:

Okay how do you figure that out?

If there are 3 doors and one has already been opened you wont choose that door.

1 goat
1 car

2 doors

50% chance of picking the right one when i went to school :huh: [/b][/quote]
Lee,
as I already explained to grimm 3 times only,
you have NOT opened the door,
you ONLY INDICATED which door you want to be opened.

I get that i only indicated but if one of the 3 doors has already been opened that only leaves 2 doors to open.

With 2 possible scenarios..

Door 1 - Goat
Door 2 - Car

I think im gonna head to bed and figure this out when i wake up again lol

this makes no sense. your probability of picking the goat would not stay the same.

instead of 1/3 doors, you have elimiated 1 door, making the new choice 1/2, or 50/50.


You are correct this far.from a mathematical perspective, it would remain constant, since it is still the original problem we are trying to solve. there could be three open doors, and the odds would still be 1/3 for the BMW.

but when you added a personal choice to it,it became a human Logic problem, and logic dictates fluid thinking, and when the third door was open, the logic problem changed. obviously the contestant seeing the goat, would shift the way she thought about the problem. She would not see it as 1/3 she would see it as 1/2 with one door being eliminated. the calculator would see it as 1/3:)

I get that i only indicated but if one of the 3 doors has already been opened that only leaves 2 doors to open.

With 2 possible scenarios..

Door 1 - Goat
Door 2 - Car

I think im gonna head to bed and figure this out when i wake up again lol [/b][/quote]
good idea!
I did exactly that, woke up,
read the correct answer and fully understand now WHY switching gets 66% chance and not 50 or 33%
;-)))

I get that i only indicated but if one of the 3 doors has already been opened that only leaves 2 doors to open.

With 2 possible scenarios..

Door 1 - Goat
Door 2 - Car

I think im gonna head to bed and figure this out when i wake up again lol [/b][/quote]
it was ony once, and not explained in the question:)

this makes no sense. your probability of picking the goat would not stay the same.

instead of 1/3 doors, you have elimiated 1 door, making the new choice 1/2, or 50/50.


You are correct this far.from a mathematical perspective, it would remain constant, since it is still the original problem we are trying to solve. there could be three open doors, and the odds would still be 1/3 for the BMW.

but when you added a personal choice to it,it became a human Logic problem, and logic dictates fluid thinking, and when the third door was open, the logic problem changed. obviously the contestant seeing the goat, would shift the way she thought about the problem. She would not see it as 1/3 she would see it as 1/2 with one door being eliminated. the calculator would see it as 1/3:) [/b][/quote]
grimm,
I could have easily pick a $100 from you by betting you,
but I won't, because you are a good sport and I am SURE you'll see WHY your logic failed,
and YES, this is a VERY hard problem to solve, because the wrong answer is sooooooo obvious!
;-))

Here are the arguments in favor of 1)

When you are presented with the choice of 3 doors,
what are the possible outcomes:

1) you pick BMW
2) you pick goat
3) you pick goat


66% chance that you were wrong on your first original pick,
2 out of 3.
Therefore,
CHANGING your door choice, will lead to positive outcome 2 out of 3 times.

Does it make sence NOW why switching is more beneficial than staying with original choice and NOT equal to 50%????
;-))

..and if you are still not convinced...
imagine 100! doors instead of 3
(logic for 100 doors is the SAME as for 3 or 3,000,000 doors)

you indicated one door and the host opened 98 doors and...
would you assume that you picked the car in 1:100 chance or the other one closed is where BMW is?
;-))))

Oh yeah and.. im stealing this question to ask on GWW lol

very simple,
as I posted in my previous post,
the chances of winni9ng the car by switching your original choice is 66%,
not 50!!!!!!!!!!!!!!!!! [/b][/quote]
the answer is probably that by switching doors, you extracate yourself from the 2/3 problem, into a whole new logic problem that puts you at 1/2.

so instead of 1/3 shot, you would have a 1/2 shot. its the elimination that is the key. logic dictates that if can readuce your odds by making the switch you should.

an easier way to look at it for me was, what if there were 10 doors, and one by one the tv host opens them, revealing nothing. he stops when he gets to two. your original odds were 1-10, those are still your odds. switching doors would make it 1/2, a more probable shot.


and to think, no math involved

yes i see where my logic failed, i forgot the #1 rule of logic problems, make the set bigger than it is, much easier to see lines on a football field than sistine chapel on the head of a pin.:)

the answer is probably that by switching doors, you extracate yourself from the 2/3 problem, into a whole new logic problem that puts you at 1/2.

so instead of 1/3 shot, you would have a 1/2 shot. its the elimination that is the key. logic dictates that if can readuce your odds by making the switch you should.

an easier way to look at it for me was, what if there were 10 doors, and one by one the tv host opens them, revealing nothing. he stops when he gets to two. your original odds were 1-10, those are still your odds. switching doors would make it 1/2, a more probable shot.


and to think, no math involved [/b][/quote]
very good,
you are now leaning in the right direction except..
if there were 10 doors,
your odds of winning the car on switch would have been...
90%!
;-))))

and yep, you could have snaked 100 bucks off of me there:) my mind works too fast at times.. sometimes the answer is right in front of you:)

hahahah,
good analogy but..
you WERE leaning in the right direction, by bringing 10 doors instead of 3 example
;-)))

pay us royalties, mofo!!!!
;-))))