Subject: The Monty Hall problem Sat May 15, 2010 6:36 am
The Monty Hall problem is a famous puzzle based on an American game show. Here it is:
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 No. 1, and the host, who knows what's behind the doors, opens another door, say No. 3, which has a goat. He then says to you, "Do you want to stick with Door No. 1, or switch to Door No. 2?" Is it to your advantage to switch your choice?
You, of course, want the car.
So, what would you do?
I'll be revealing the "secret" soon, so just say what you would do and don't ruin it for other people by looking it up. (If you already know it, don't reveal it either, because people might still be trying to figure it out themeselves)
Cormster Sage
Posts : 1914 Credits : 33919 Reputation : 6 Join date : 2010-01-30 Age : 27 Location : Northern Ireland
Subject: Re: The Monty Hall problem Sat May 15, 2010 9:13 am
Routledge: *puts on tinted spectacles* There is not yet enough evidence to deem him murderous, yet all gameshow hosts are miserable misers and deserve a little stabbing.
Cormster Sage
Posts : 1914 Credits : 33919 Reputation : 6 Join date : 2010-01-30 Age : 27 Location : Northern Ireland
Subject: Re: The Monty Hall problem Sun May 16, 2010 4:55 am
I think it's time to reveal: THE ANSWER!
Probably one of the easiest ways to explain how this works, is by simulating it with three playing cards from a normal deck.(Me and my playing cards ) (Also, you can get a deck of playing cards and try it for yourself too if you want)
Let's say, the Ace of spades represents the car. 2 random cards represent the goats.
Now, seeing as there are 2 random cards, there's a 2 in 3 chance of you picking one of them, right?
And seeing as there's one Ace of spades, there's a 1 in 3 chance of you picking it, right?
So, when you start, there's more of a chance of you picking a random card(A goat) than the Ace of Spades(The car)
This also means, that when you take away one of the random cards, if you switch your choice, the probability of getting the car changes to 2 in 3.
That last bit confused you didn't it?
Well here's a diagram to help you understand:
So, this means, that there's a 2 in 3 chance of you getting the car if you switch, but only a 1 in 3 chance of you getting the car if you stick with your original answer.
So, it's better to switch!
If you have any questions, or if you still don't get it, just say and I'll answer your queries as well as I can.
Subject: The Monty Hall problem 
Sat May 15, 2010 6:36 am
(If you already know it, don't reveal it either, because people might still be trying to figure it out themeselves) 
