Thursday, January 1

The Monty Hall Problem

Apparently, I enjoy Probability Mathematics.

Here's one that came across yesterday:

You are on a gameshow, and there are three doors. Behind one door, there is a car. Behind the other two are goats. You are asked to pick the door you hope the car is behind. You make your choice.

The host then shows you what's behind one of the other doors. Naturally, he shows you some goats. Now there are two doors left, one of which is the door you picked. Behind one is the car, behind the other, goats.

The host gives you the option of sticking with the door you picked, or switching your choice to the other door.

Now, it seems as if this chance to switch would be fairly inconsequential. It seems as if, with two doors left, it's a 50/50 chance that you are right, so what's the point of switching. Or, what's the harm of switching?

But it's not a 50/50 proposition.

In fact, if you do switch, your chance of winning the car increases to 66%.

So, if you're ever in situations like this, always choose to switch and you'll be right 2 out of 3 times.


Nils Ling said...

Oh, I know this one. Now, first you take the goats across, then you come back and take the car across, but on the way back you take the goats ... no, wait ... first you take the CAR across ... no, hang on ...
Ah, screw it, I'll take the curtain that Carol Merrill is standing in front of.
Happy New Year ... see yez at the Levees!

Elliot said...

Dear Monty Hall
My name is Elliot Sarlo from City Island Bronx New York. I Remember you used to be the host the host of Let's make a deal,Beat the Clock,SplitSecond where they had the fake windows clouds and ski,+other games you hosted.So is there any way you can get me the $25,000 Pyramid Game with Dick Clark's picture on it to my house to address 570 City Island Avenue. Bronx New York. 10464. Nice meeting you.
Elliot Sarlo

Rob MacD said...

Sorry Elliot, but I have no more $25,000 Pyramid games with Dick Clark's picture on it. Would you settle for the Definition home game with a charcoal drawing of Jim Perry?

Kevin said...

Does the Definition home game come with the soundtrack... ... I think Quincy Jones wrote the theme...

Rob MacD said...

No soundtrack, Kevin, but it comes with the sheet music and a lesson on how to hum.

Kevin said...

That reminds me of the scene in A Mighty Wind where they have a moment of humming rather than a moment of silence for the deceased. The particularily dense PR person (one of the lesbian dog owners from Best in Show) is unable to hum correctly and makes this odd open-mouthed noise. SHE needed a lesson on how to hum.