A brain challenge that people get pretty passionate about

[Guest]

3 minutes ago, zil said:

Uh huh.  I'm gonna go pick up my new fountain pen and ink at the post office now.

LOL!  Oh come on.  When I took computer programming as a major, I still had to take kinematics as part of the course load.  Didn't you?

[zil]

46 minutes ago, Carborendum said:

LOL!  Oh come on.  When I took computer programming as a major, I still had to take kinematics as part of the course load.  Didn't you?

I didn't take programming in college.  My ACT scores were high enough that I didn't even have to take math.  I only took a couple science classes - the required basic biology and chemistry (and geography, I think).  I tripped into programming by accident and am entirely self-taught in that particular skill.

[Rob Osborn]

1 hour ago, JohnsonJones said:

This is also sort of counter intuitive.  When you originally can choose a door, you have a 1/3 chance of being correct.  When he then reveals what is behind one of the doors you did NOT choose, that leaves two doors.  If you choose the other door, you have a 50/50 chance of being correct, which is greater than your chances previously (50% is greater than 33.333...%).  The reason is he has revealed one answer that is absolutely not correct, where as before, you had a 2 in 3 chance of choosing an incorrect one.  Furthermore, he is going to reveal one that is NOT correct, rather than one that IS correct. (which affects it as Zil already notated).  It is because of this action of his (if it were equal chances of him revealing the right door rather than what was a wrong door...it could change this...but the game is he reveals a WRONG door) that makes the best choice (but not always the right choice...if that makes sense) to always do the trade.

It can have a little bit more complex explanation than that, but I've been longwinded enough for this thread already...

Yep, you always trade your original door cause 50% is better than 33%. 

[mordorbund]

The 50% idea is inaccurate. It's actually a 2/3 chance that the other door has the prize (and 1/3 that your door has the prize).

If it was really 50/50, then it wouldn't matter if you changed doors or not. The one you had would be just as likely as the unknown door. If the unknown door was 50%, and the door you had was still 33%, then where is the other 17%? It's not behind the open door because there's a 0% chance there's a prize there. So where did it go?

[JohnsonJones]

48 minutes ago, mordorbund said:

The 50% idea is inaccurate. It's actually a 2/3 chance that the other door has the prize (and 1/3 that your door has the prize).

If it was really 50/50, then it wouldn't matter if you changed doors or not. The one you had would be just as likely as the unknown door. If the unknown door was 50%, and the door you had was still 33%, then where is the other 17%? It's not behind the open door because there's a 0% chance there's a prize there. So where did it go?

I believe you are right, but I was trying to be more concise because I can go on and on and on about something (if no one had noticed). 

I could have expounded on that for at least 5 paragraphs explaining it!!!     !

Edited December 6, 2017 by JohnsonJones

[Guest]

8 hours ago, mordorbund said:

The 50% idea is inaccurate. It's actually a 2/3 chance that the other door has the prize (and 1/3 that your door has the prize).

If it was really 50/50, then it wouldn't matter if you changed doors or not. The one you had would be just as likely as the unknown door. If the unknown door was 50%, and the door you had was still 33%, then where is the other 17%? It's not behind the open door because there's a 0% chance there's a prize there. So where did it go?

Statistically, the following website has been collecting data on everyone who tries the game

https://math.ucsd.edu/~crypto/Monty/monty.html

This game has been going for years now.  And there is a pretty large sample group (about 1000).  Those who choose to switch to Door C are twice as likely to get the new car instead of the goat.

Edited December 6, 2017 by Guest

[Rob Osborn]

2 hours ago, mordorbund said:

The 50% idea is inaccurate. It's actually a 2/3 chance that the other door has the prize (and 1/3 that your door has the prize).

If it was really 50/50, then it wouldn't matter if you changed doors or not. The one you had would be just as likely as the unknown door. If the unknown door was 50%, and the door you had was still 33%, then where is the other 17%? It's not behind the open door because there's a 0% chance there's a prize there. So where did it go?

Spot on my friend, spot on! Its good we have someone doing the math.

Edited December 6, 2017 by Rob Osborn

[askandanswer]

15 hours ago, NeuroTypical said:

That show was R-rated for good reason.  It has the advantage of having a parody made of it, that condenses it down to 15 minutes, has all the poignancy and brilliance, with zero violence/language/nakedidity.

 

15 hours ago, anatess2 said:

The both of you have gone way beyond the social media standard for nerdness and has penetrated the world of autists.

With all this talk of nakedidity and autism this forum has become a very naut y istic place to be today

[zil]

9 hours ago, JohnsonJones said:

I believe you are right, but I was trying to be more concise because I can go on and on and on about something (if no one had noticed). 

I could have expounded on that for at least 5 paragraphs explaining it!!!     !

For the record, this is the first post by JJ that I've read in it's entirety.

(That may be under-exaggeration.)

7 hours ago, Carborendum said:

Those who choose to switch to Door C are twice as likely to get the new car instead of the goat.

But if I got the goat, I'd never have to mow the lawn again!

Edited December 6, 2017 by zil

[Vort]

Re: the Monty Hall Problem:

I found it helpful to consider Monty Hall standing before a billion doors, asking which one had the Brand New Car®. After I pick one (with a one-in-a-billion chance of being correct), Monty then opens 999,999,998 other doors to reveal booby prizes consisting of various goats and empty shopping carts. He then asks me if I want to switch. Am I really supposed to believe that I might as well stick with my original choice, because now it's a 50/50 proposition?

[Rob Osborn]

 

1 hour ago, Vort said:

Re: the Monty Hall Problem:

I found it helpful to consider Monty Hall standing before a billion doors, asking which one had the Brand New Car®. After I pick one (with a one-in-a-billion chance of being correct), Monty then opens 999,999,998 other doors to reveal booby prizes consisting of various goats and empty shopping carts. He then asks me if I want to switch. Am I really supposed to believe that I might as well stick with my original choice, because now it's a 50/50 proposition?

Sure, go ahead

Edited December 6, 2017 by Rob Osborn