If you can figure this out...you are a genius

[BigDumbHells]

Try this one out, and be sure to explain your answer because that is the only way it matters:

Suppose you're on a game show, and you're given the choice of three doors. Behind one door is a car, behind the others, goats. You pick a door, say number 1, and the host, who knows what's behind the doors, opens another door, say number 3, which has a goat. He says to you, "Do you want to pick door number 2?" Is it to your advantage to switch your choice of doors? Why or why not?


They say only 5% of the population will come to the correct reasoning of this problem. Can you?

[SwoleOne]

switch.. you have a higher probability of winning

[SwoleOne]

actually i dunno there is no right answer

^^ final answer?

[Antidote]

it wont matter its all random placement of the car.

you have a 50/50 chance

[Fyradiem]

he is trying to persuade you to change, keep your ****ing door.

[BigDumbHells]

it wont matter its all random placement of the car.

you have a 50/50 chance

This is what the normal person would think. Wrong.

[SwoleOne]

^ yeah, that isn't the logic i used, but i think the answer is simple .. THERE IS NO CORRECT ANSWER

[mickey mouse]

you have to change the door because people who switch have a higher probability to get the right one

why

i donno

but it's a rly

[BigDumbHells]

actually i dunno there is no right answer

^^ final answer?

There is a right answer. I am looking for the short version of the answer (either keep the door or switch) and why one would be better.

[LinkS]

I would switch my door since he opened door 3 and knew there was a goat so hes problably helping me out..

[InvidGurab]

With one door out of the way it's a 50/50 split choice.

[KingWay]

This is what the normal person would think. Wrong.

Wrong.

[NuggzTheNinja]

Try this one out, and be sure to explain your answer because that is the only way it matters:

Suppose you're on a game show, and you're given the choice of three doors. Behind one door is a car, behind the others, goats. You pick a door, say number 1, and the host, who knows what's behind the doors, opens another door, say number 3, which has a goat. He says to you, "Do you want to pick door number 2?" Is it to your advantage to switch your choice of doors? Why or why not?


They say only 5% of the population will come to the correct reasoning of this problem. Can you?

You have a 66% chance of winning if you switch doors, 33% if you stay.

[sumguy]

I'd switch doors. Better chance of winning. You know he's not going to open the door with the car.

[LinkS]

**** that ill pick door #3

[BigDumbHells]

You know he's not going to open the door with the car.

That would defeat the whole purpose of this problem.

[sumguy]

That would defeat the whole purpose of this problem.

Yep, your odds are better if you switch.

[ShtUp&Sqt]

Your original guess had a 66% chance the you were wrong. Because the Host eliminated 1 of the incorrect doors for you, it is to your advantage to switch. You will be right 2/3rd's of the time. If you don't believe me write a progam that does just what the original problem says and you will see.

[KingWay]

Can someone explain why theres a better chance if you switch.

[tim1477]

You have a 66% chance of winning if you switch doors, 33% if you stay.

I believe this is the correct answer, but I can't figure out why.

It's a 33% chance in the beggining. 1/3 chance for each door. Simple.
Take away one of those thirds, and you are not left with 2/3, but rather now it becomes a 1 in 2 shot. I can't figure out why it would be any other reason. It seems like you have an equal shot at both.

[SwoleOne]

you want to switch... you have a higher probability of of guessing the correct door, 2-1 ratio, 66% chance..

[BigDumbHells]

This is a very contraversial problem, with good reason too.


The answer (and a program to show it) when I return from working out!!!

[sumguy]

I believe this is the correct answer, but I can't figure out why.

It's a 33% chance in the beggining. 1/3 chance for each door. Simple.
Take away one of those thirds, and you are not left with 2/3, but rather now it becomes a 1 in 2 shot. I can't figure out why it would be any other reason. It seems like you have an equal shot at both.

That wouldn't add up to 100%, though. The odds have to add up to 100%. If two doors are left and one is 1/3 chance, the other must be 2/3.

And one must be 1/3 because you chose it randomly out of 3 doors.

[DanGK]

you picked the right door. silly host trying to mislead you

[ShtUp&Sqt]

Can someone explain why theres a better chance if you switch.

Because your original choice had a 2/3 of a chance of being wrong. You didn't gain any new infomation by him showing you a wrong answer. It is to your advantage to switch

[LinkS]

ANSWER

Zomg ****ing google owned http://www.cut-the-knot.org/hall.shtml

[NuggzTheNinja]

I believe this is the correct answer, but I can't figure out why.

It's a 33% chance in the beggining. 1/3 chance for each door. Simple.
Take away one of those thirds, and you are not left with 2/3, but rather now it becomes a 1 in 2 shot. I can't figure out why it would be any other reason. It seems like you have an equal shot at both.

Draw three doors on the sheet or paper. Pick a door, say, door one.

Draw a bracket around doors 2 and 3.

There's a 1/3 chance it'll be in each door at the start of the game. Now, you selected door one, so there's a 1/3 chance it'll be behind there.

Of the other two doors, a 2/3 chance in total, each door being a 1/3 chance. By eliminating one of those doors, you're 100% sure it isn't behind the eliminated door.

Now, probability is always equal to 1 given all possible outcomes. Since your 2/3 chance had been previously divided between two doors and is now only divided amongst one door, there is a significantly higher probability of you choosing the correct door if you switch.

On your drawing, cross out door 3. You still have 2/3 written above doors 2 and 3. This probability is entirely given to door 2.


I didn't believe it would work until I tried it.

[Donster]

Piitb?

[tim1477]

I worked it out, and I understand where the logic comes from now, but it STILL doesn't make sense. Once the game host cancels out door number three, its out of the picture. It comes down to two doors. 1 in 2 right? Heres my diagram

[ShtUp&Sqt]

This is a very contraversial problem, with good reason too.


The answer (and a program to show it) when I return from working out!!!

It is not controversial at all....It is a mathematical probability problem....not the Da Vinci Code. The answer is switch (See Above)