The Riddle That Drove H1roshi Mad.

[hungrybox]

YOU

Are on a game show.

In this show, you can win a car.

There are three doors.

Two of the doors have a goat.

One door has a car.

(Pick a door, 1, 2, or 3.)

Let's say you pick 3. (It doesn't matter)

The host says, "You have picked door 3. I will open door 1 to reveal...a goat!"

*The host always opens a door you didn't pick to reveal a goat.

You now know that door 1 has a goat, and you picked door 3.

The host asks you, "Now that you know there is a goat in door 1, do you want to stay with door 3 or switch to door 2?"

Which would give you better odds of winning the car?

STAYING?

Or

SWITCHING?


***I want someone non-WATO to figure this one out without researching it.***

 

[CaptainCrunch]

Hahahaha you're like gonna start a smash war with this ish. Lol

 

[exarch]

I don't feel like doing the calculations again, but we did this last semester in my probability course. IIRC, switching gave you the better odds.

Of course, if I wasn't in the middle of finals I might spend more time verifying this again.

Where's my other math heads?

 

[Gmoney]

You should switch. It changes your probability of winning the car to 2/3 from 1/3, but this **** is stupid anyways.

 

[Gerbil]

Switch. As said above, your odds increase.

Had Discrete Math this semester, this was one of our problems

 

[Zoro]

I still say its 50/50

 

[CaptainCrunch]

I still say its 50/50

Think Zoro Think. lol.

 

[derf]

i remember somebody emailed me this problem from that IQ chick's webpage a ways back. i got it wrong at first, but switching is the way to go

 

[JackHouser]

cant you switch back to the original choice again lol?

 

[everlasting yayuhzz]

Switching gives you better odds.

If door A and C have the goat, and you pick A, C is revealed, you can switch and get the car.

If door A and C have the goat, and you pick B, one of the remaining goats is revealed, and you switch and lose the car.

If door A and C have the goat, and you pick C, A is revealed and you switch to win the car.



Odds say that switching gives you a better chance than staying.

 

[Zoro]

If you pick any door a goat will be revealed there will be 2 doors remaining

now you have the option to pick or stay

there is ONE goat and ONE car
there are two doors

if you stay there could be a car if you switch there could be a car

its 50/50

mathematically 2/3 makes sense
logically it doesnt!

 

[Gerbil]

OK. I decided to elaborate on this.

This problem or "riddle" is commonly referred to as the Monty Hall Three-Door Puzzle.

I am copying straight out of my text book for all to see lol.

Riddle:

Suppose yo are a game show contestant. You have a chance to win a large prize. You are asked to select one of three doors to open; the large prize is behind one of these three doors and the other two are losers. Once you select a door, the game show host, who knows what is behind each door, does the following. First, whether or not you selected the winning door, he opens one of the other two doors that he knows is a losing door (selecting at random if both are losing doors). Then he asks you whether you would like to switch doors. Which strategy should you use? Should you change doors or keep your original selection, or does it not matter?

The Solution:

Spoiler

The probability you select the correct door (before the host opens a door and asks you whether you want to change) is 1/3, because the three doors are equally likely to be the correct door. The probability this is the correct door does not change once the game show host opens one of the other doors, because he will always open a door that the prize is not behind.
The probability that you selected incorrectly is the probability the prize is behind one of the two doors you did not select. Consequently, the probability that you selected incorrectly is 2/3. If you selected incorrectly, when the game show host opens a door to show you that the prize is not behind it, the prize is behind the other door. So, by changing doors, the probability you win is 2/3. In other words, you should always change doors when given the chance to do so by the game show host. This doubles the probability that you will win.

<3 Exarch

 

[everlasting yayuhzz]

If you pick any door a goat will be revealed there will be 2 doors remaining

now you have the option to pick or stay

there is ONE goat and ONE car
there are two doors

if you stay there could be a car if you switch there could be a car

its 50/50

mathematically 2/3 makes sense
logically it doesnt!

Stop being wrong.

 

[MattDotZeb]

So, uh, yeah.
Insanely obvious 21 reference anyone?
This exact riddle/thing was in 21.

 

[Gerbil]

So, uh, yeah.
Insanely obvious 21 reference anyone?
This exact riddle/thing was in 21.

you totally skipped over my post.

This is a game show riddle lol, many many many years old XD. 21 didn't do it first, I promise

 

[Zoro]

I dont think im wrong

your just looking at it differently than me

for me its 50 50 because its either ONE of TWO doors 1 of two is one half, one half is fifty fifty chance.

 

[MattDotZeb]

Oh, no. I didn't think 21 did it first. Still, anyone who didn't know of it and saw 21 recently (me) would have noticed.

 

[hungrybox]

So, uh, yeah.
Insanely obvious 21 reference anyone?
This exact riddle/thing was in 21.

i didn't watch 21

 

[Mankosuki]

I'd have to agree with Zoro. Every time your allowed to pick a door, the probability should be reset. It really doesn't matter that there used to be more available, right now there's only two to choose from. Would your chances have been improved even more if there were more than two chances and you switch every time?

What's the difference between having passed 1 round and having passed 10 rounds, if they both end in a 50-50 choice of two doors?

 

[Ryanarius]

I think its switch. Just imagine if there were 100 doors and 99 of them had goats but the gameshow host revealed that 98 of the doors you didn't pick had goats. Obviously your odds are better to switch at this point. I could be wrong but it makes sense to me at least.

 

[hungrybox]

wait till crunch comes to explain it

 

[EternalCrusade]

Zoro is making sense to me. At first, you have a 1/3 chance of picking the door with the car. Whether you picked the car or not, the host shows you one of the other two doors and it's a goat. So now, there's only two doors left; one with a car and one with a goat. Your chances of getting the car increased to 1/2 when the host showed you that door number one wasn't the car. You mine as well of started off with two doors and when you chose when, he asked "Are you sure you don't want to switch?"

EDIT: hasnt anyone here watched an episode of Deal or No Deal?

 

[BEHR]

There all goats the show was a lie.

 

[Zoro]

Its like even if there is a 3rd door it doesnt matter at all
one of the doors will be a eliminated which leaves you with 2

you already picked one of the two if you stay you have a one out of two chance of getting a car
if you switch to the other door it is the SAME CHANCE

there is no favoring odds

it will always be 1 out of 2!

Someone please convince me on how one side of a coin is more likely to land face up than the other

you all dont make any sense to me

stop being wrong please

 

[Finch]

This seems like crap to me. In the beginning you are trying to find the one Y among 2 Ns and one Y, but one of the Ns will always be eliminated. Thus the option to switch will always just be between Y and N. I get the math, but it's crap.

I bet if someone ran a program that always switched the probability would come out 50/50.

 

[Laijin]

This was in that movie 21.
You stay because you now have a 66.66 chance of being right

 

[theONEjanitor]

Zoro is making sense to me. At first, you have a 1/3 chance of picking the door with the car. Whether you picked the car or not, the host shows you one of the other two doors and it's a goat. So now, there's only two doors left; one with a car and one with a goat. Your chances of getting the car increased to 1/2 when the host showed you that door number one wasn't the car. You mine as well of started off with two doors and when you chose when, he asked "Are you sure you don't want to switch?"

EDIT: hasnt anyone here watched an episode of Deal or No Deal?

Lemme explain this in a simpler way to people.

Since there are three doors, the probability that you selected wrong is double the probability that you selected the right one. Meaning it is twice more likely that the door you chose was WRONG. Meaning you PROBABLY chose the wrong door.

This remains true, even after you are shown the other door that is incorrect. It still remains true that you PROBABLY selected incorrectly from the beginning. Because there was a 2/3 chance of you doing so. That doesn't change. Given that you PROBABLY selected incorrectly, it makes sense probability wise that you should switch, because if you selected incorrectly, which you PROBABLY did according to your odds, that means the other door IS the correct door.

if you end up having selected the right door from the very beginning, you will have simply done the improbable.

its more likely you have the wrong door, because it WAS from the very beginning. That doesn't change.

 

[theONEjanitor]

This seems like crap to me. In the beginning you are trying to find the one Y among 2 Ns and one Y, but one of the Ns will always be eliminated. Thus the option to switch will always just be between Y and N. I get the math, but it's crap.

I bet if someone ran a program that always switched the probability would come out 50/50.

its been done, and it does in fact come out as 66 percent.

 

[Gerbil]

Orrrrrrrr everyone could look on page one, and look at my SPOILER tagged type, and see that I have already given the exact solution, straight from a Discrete Math book.

>.>

 

[Frames]

Yea, I've definitely seen that puzzle before...

Good riddle, but it's definitely 1/3rd, and to answer your question it wouldn't matter if you stayed or switched since it would give the same probability either way so...yea.

 

[hungrybox]

thank you vijin

switching>staying

 

[EternalCrusade]

Lemme explain this in a simpler way to people.

Ouch. Don't insult people's intelligence.

Since there are three doors, the probability that you selected wrong is double the probability that you selected the right one. Meaning it is twice more likely that the door you chose was WRONG. Meaning you PROBABLY chose the wrong door.

This remains true, even after you are shown the other door that is incorrect. It still remains true that you PROBABLY selected incorrectly from the beginning. Because there was a 2/3 chance of you doing so. That doesn't change. Given that you PROBABLY selected incorrectly, it makes sense probability wise that you should switch, because if you selected incorrectly, which you PROBABLY did according to your odds, that means the other door IS the correct door.

if you end up having selected the right door from the very beginning, you will have simply done the improbable.

its more likely you have the wrong door, because it WAS from the very beginning. That doesn't change.

If this is the case, then shouldn't you decide on a door first in your mind and then switch from your original choice?

 

[Laijin]

How does this relate to smash
This is a spam topic.

 

[Mankosuki]

How does this relate to smash
This is a spam topic.

We're developing for mindgames.

 

[Zoro]

I see how you think

Now understand how i think

You have three blank cases one of them contains melee the superior form of brawl which is in the other two cases.

I ask you to pick one

you pick number 2
I then remove 3 as it is brawl

Now in front of you
there is only 2 cases to choose from

There is no 3rd option
Stay is case number 2
Switch is case number 1

Stay = 1
Switch=1

the probability no matter how you look at this is
ONE out of these TWO has the greatest game in the world (melee)
in fact you can flip a coin to choose

Heads is case 2 Tails is case 1
it would be the exact same thing

THERE IS A 50% CHANCE OF GETTING MELEE OR BRAWL AT THIS EXACT MOMENT IN TIME

there is a 1/3 chance of me being wrong IF ONE OF THE CASES WASNT ELIMINATED
but it was and now it is a 1/2 chance. Regardless of if im wrong or not switching will not win me melee. it is complete 50/50 nothing can change 2 from being 2!

Everyone is trying to think backwards when in reality its simple

 

[EternalCrusade]

Switching gives you better odds.

If door A and C have the goat, and you pick A, C is revealed, you can switch and get the car.

If door A and C have the goat, and you pick B, one of the remaining goats is revealed, and you switch and lose the car.

If door A and C have the goat, and you pick C, A is revealed and you switch to win the car.



Odds say that switching gives you a better chance than staying.

I completely didn't see this post until now, now I understand the logic behind it. I think that's the whole point of this puzzle, is that at first you think it's 50/50 no matter what, but after a little thinking you get it. I love puzzles like these...

...and Deal or No Deal is now flawed lol (at least at the end where you're allowed to switch cases)

 

[Frames]

I see how you think

Now understand how i think

You have three blank cases one of them contains melee the superior form of brawl which is in the other two cases.

I ask you to pick one

you pick number 2
I then remove 3 as it is brawl

Now in front of you
there is only 2 cases to choose from

There is no 3rd option
Stay is case number 2
Switch is case number 1

Stay = 1
Switch=1

the probability no matter how you look at this is
ONE out of these TWO has the greatest game in the world (melee)
in fact you can flip a coin to choose

Heads is case 2 Tails is case 1
it would be the exact same thing

THERE IS A 50% CHANCE OF GETTING MELEE OR BRAWL AT THIS EXACT MOMENT IN TIME

there is a 1/3 chance of me being wrong IF ONE OF THE CASES WASNT ELIMINATED
but it was and now it is a 1/2 chance. Regardless of if im wrong or not switching will not win me melee. it is complete 50/50 nothing can change 2 from being 2!

Everyone is trying to think backwards when in reality its simple

Look, it's called a riddle for a reason, it's supposed to be illogical. It would be 1/2 if you considered only those two doors; the other door is eliminated completely from the equation. The reason it's a third is simple: if you have 3 doors, and one has mankind's greatest achievement (melee), and then the other two doors have brawl, then one out of 3 doors has melee. The only difference between that and this is that you already know that one door has brawl. The odds would be the same no matter how you switch, it would be 1/3.

 

[Finch]

its been done, and it does in fact come out as 66 percent.

well that blows my mind because logically it does not make sense. I understand the 1/3 or 2/3 thing, but...wtf

I don't give a **** I'm an English major and I don't have to deal with this **** I just have to tell you why Tolstoy is awesome and ****

**** math. This only makes me mad because I was good at math in HS. I got a 5 in AP Calc.

.999~ =/= 1

 

[Zoro]

Your looking at the whole thing
im looking at two cases

your lookin at 3
2 are starin u right in the face and your still lookin at the one I took thats in my hand like it actually has any part to this problem any more.

Your completely ignoring the fact that you know without a doubt that one is not what your lookin for.


Eternal has made me think another thing

People dont actually understand this
they just have people explain it to them sooooooooo many times that they have to say they get it
I get it too i just dont agree with your reasonings. Hiroshi had hungrybox and cpt crunch explain it to him like literally 15 times and he didnt agree every time finally he gave up and said he understood it.
I think you give up too easy theres no way im going to believe one out of the two has more chances of being melee.

 

[MusicalMike]

I bet you the car is **** if the other two prizes are goats

I'm taking a ****ing goat.