So you think you have a logical mind?

[corydoras]

I have three paper cups upside down in front of me on a table, numbered 1, 2 and 3.

 

One of them has a £10 note inside it. If you choose the cup with the tenner under it you can keep it. I know which cup contains the £10.

 

Now let's say you choose cup number 3.

 

I then show you one of the empty cups, say cup number 1 and offer you the choice of sticking to your original choice of cup 3 or switching to cup 2.

 

Is it to your advantage to switch cups or not.

 

Give a reason for your answer.

Edited September 4, 2009 by corydoras

[Andy_1984]

i voted no but realised i should have answered "it makes no difference"

 

my reason: the odds are fifty fifty since you took cup one away and i have no idea where the tenner is .my choice would be totally random to begin with so why bother changing........

Edited September 4, 2009 by Andy_1984

[chesters1]

it makes no difference it isnt my tenner so i have nothing to lose

on the other hand you do so will make it as hard for me to get your tenner as you can (by fair means or foul)

[corydoras]

it makes no difference it isnt my tenner so i have nothing to lose

on the other hand you do so will make it as hard for me to get your tenner as you can (by fair means or foul)

No chesters, no trick questions, not a scam.

[morue]

No chesters, no trick questions, not a scam.

[/quote

 

Monty Hall Paradox

The Monty Hall problem is a probability puzzle based on the American television game show Let's Make a Deal. The name comes from the show's host, Monty Hall. The problem is also called the Monty Hall paradox, as it is a veridical paradox in that the result appears absurd but is demonstrably true.

 

The problem can be unambiguously stated as follows:

 

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. The car and the goats were placed randomly behind the doors before the show. The rules of the game show are as follows: After you have chosen a door, the door remains closed for the time being. The game show host, Monty Hall, who knows what is behind the doors, now has to open one of the two remaining doors, and the door he opens must have a goat behind it. If both remaining doors have goats behind them, he chooses one randomly. After Monty Hall opens a door with a goat, he will ask you to decide whether you want to stay with your first choice or to switch to the last remaining door. Imagine that you chose Door 1 and the host opens Door 3, which has a goat. He then asks you "Do you want to switch to Door Number 2?" Is it to your advantage to change your choice? (Krauss and Wang 2003:10)

 

As there is no way for the player to know which of the two remaining unopened doors is the winning door, most people assume that each of these doors has an equal probability and conclude that switching does not matter. In fact, the player should switch—doing so doubles the probability of winning the car from 1/3 to 2/3.

[corydoras]

Well done morue, all of those who voted thought it was 50-50 were wrong, but don't take it to heart, most folks assume that because there are only 2 cups left it is 50-50.

[chesters1]

and i was also right for not believing anything

logically to believe anything is not logical

to give someone the chance of getting your tenner even more illogical

Edited September 5, 2009 by chesters1

[Chris Plumb]

At the begining of the game you have a 1 in 3 chance of winning. If you have picked the winning cup and switch you lose - but there's only a 1 in 3 chance of this happening. If you pick a non winning cup and switch you will always win as you are never shown the winning cup only the other non-winning one.

 

 

C.

[GlennB]

Yes, switch.

It's an example of the 'principle of restricted chioce'. You were bound to show me an empty cup (you wouldn't show me the £10, obviously), so the fact that have shown me a particular empty cup suggests the £10 is under the other one.

 

Keen bridge players will know this one

Edited September 5, 2009 by GlennB

[chesters1]

but you dont know if the unseen cup (your first choice) has the tenner ,if you base your action on an empty cup you could end up with the other cup being empty .

why bother? logic says you can get the tenner after clumping its owner to the floor ,logically the owner wouldn't put a tenner under any of them just in case you win

Edited September 5, 2009 by chesters1