Stick or Switch?

Does the compère always open another door? Or is he doing it because he knows what is behind each door and he knows you have chosen the Ferrari.

mid he doesn’t then I would argue there are two doors left one has a goat and one has a Ferrari behind and therefore the answer is it doesn’t matter as you have a fifty fifty chance at that point.

the door the compère opens is no longer relevant and any statistics including that door wouldn’t matter surely?
 
FatCat said:
Does the compère always open another door? Or is he doing it because he knows what is behind each door and he knows you have chosen the Ferrari.

mid he doesn’t then I would argue there are two doors left one has a goat and one has a Ferrari behind and therefore the answer is it doesn’t matter as you have a fifty fifty chance at that point.

the door the compère opens is no longer relevant and any statistics including that door wouldn’t matter surely?
Click to expand...
The host always opens a door with a goat behind it.
 
My logic is this - at the point the compère opens the door with a goat behind that door is irrelevant. You are no longer choosing between three doors you are choosing between two. Your original choice or the remaining door - one has a goat behind it one a Ferrari - surely the odds on you picking the Ferrari are fifty/fifty?
 
When you initially pick a door, you have a 1/3 chance of success (and the doors you don't pick have a 2/3 chance of success).

When the compere knowingly opens a door with a goat, the whole 2/3 chance of success is transferred to the remaining door, meaning you are twice as likely to succeed if you switch.
 
goalscrounger said:
When you initially pick a door, you have a 1/3 chance of success (and the doors you don't pick have a 2/3 chance of success).

When the compere knowingly opens a door with a goat, the whole 2/3 chance of success is transferred to the remaining door, meaning you are twice as likely to succeed if you switch.
Click to expand...
I kind of get that but he’s never gonna pick the Ferrari door so why does his choice have any relevance. You are talking about two doors with a fifty fifty chance between which one has the prize behind it.
 
Switch every time!
Your answer is based on variable change, when you are asked the first time you have a 33.3% chance, however, when one of the other doors are opened you then have a 66.6% chance if you switch, rather than the original 33.3% if you stay with your initial choice.

I beleive its called the Monty Hall Problem and is mentioned in the movie 21 with Kevin Spacey!
 
You must log in or register to reply here.
Back
Top