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SoCoder -> Link Home -> Just for Fun


 
Phoenix
Created : 26 March 2010
Edited : 26 March 2010

The Monty Hall Problem



https://en.wikipedia.org/wiki/Monty_Hall_problem
A problem which leaves everyone stumped.

"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 pick door No. 2?" Is it to your advantage to switch your choice?"

Answer: > Reveal 🔎

 

Comments


Friday, 26 March 2010, 11:54
Jayenkai
I saw that on Horizon once.. It was really freakin' weird!
Friday, 26 March 2010, 11:57
Jayenkai
Here it be...


View on YouTube
Friday, 26 March 2010, 15:38
spinal
"We are living in a four dimentional doghnut!"
"can you bake such a thing?"
Tuesday, 30 March 2010, 12:04
CodersRule
Yeah I saw a video explaining it a year or two ago. It actually makes some sense!
Tuesday, 30 March 2010, 19:35
mindstorm8191
I agree, the video makes sense. You have a 2 in 3 chance of picking the goat on the first decision, and when one of the goats is cleared, if you chose a goat on the first decision, the car can only be in the other cup. You then have 2 in 3 chances of winning the car. (I couldn't watch the whole video).
Wednesday, 31 March 2010, 07:08
CodersRule
I like thinking of it percentage-wise.
33% = chosen the car
66% = chosen a goat

If he takes one of the goats away, it's STILL a 33% chance that you have ALREADY picked a car.
And a 66% chance you have a goat.

If you swap, there's a 66% chance you have the car and a 33% chance you have the goat.

Poof.
Saturday, 03 April 2010, 05:21
Sticky
I disagree with this. The whole premise behind it being to your advantage to swap is KNOWING the other person, who set up the challenge, will always reveal a non-valuable prize. As such, it's only really valid in the situation where it's you playing against someone else.

Whereas, in the far more likely scenario where there's three choices and no conscious decision on which cup is revealed, and it's left entirely to chance, it wouldn't make any difference as to whether you stayed with your initial choice or swapped to the alternative once the first cup has its prize revealed.
Saturday, 03 April 2010, 05:22
CodersRule
Whereas, in the far more likely scenario where there's three choices and no conscious decision on which cup is revealed, and it's left entirely to chance, it wouldn't make any difference as to whether you stayed with your initial choice or swapped to the alternative once the first cup has its prize revealed.


But that isn't the Monty Hall problem.
Saturday, 03 April 2010, 05:51
Sticky
Fair enough, in the context of the Monty Hall problem it's right, but if you consider it on a larger scale outside the Monty Hall problem it's going to make no difference whether you switch or not.
Saturday, 03 April 2010, 05:56
Jayenkai
.. That's a bit like saying "The universe might very well have started with The Big Bang, but that doesn't effect my cheesecake."
Monday, 05 April 2010, 05:44
CodersRule
Fair enough, in the context of the Monty Hall problem it's right, but if you consider it on a larger scale outside the Monty Hall problem it's going to make no difference whether you switch or not.


Say you have the exact same situation, with the cups, and the other person reveals a goat. (Not knowing where the car was.)
You'd still have an advantage to switch!