Ok, Peter, I'll try to be more clear you have 3 doors. Each one has 1/3 of possibility of containing the prize. You pick one door. Your chance of winning is 1/3, right? And your chance of losing is 2/3, right? So, the host opens an empty door. You'll win without changing your door if you picked the correct one first (1/3 of posibility). And you'll lose without changing your door if you picked one of the incorrects first (2/3 of posibility). So, you'll win more times if you change your door. Is it clear now? Ok, if you want, you can write down all posibilities and see for yourself how many times you'll win if you don't change your choice (I actually made that when I first saw this problem). If it's not clear, please tell me and I'll think about a better explanation... Pedro
pjgat09 <[EMAIL PROTECTED]> escreveu: I am assuming we are using varient one. Unless varient 2 means that all the time he will get an empty door, then they are both the same. Anyways, Why do you still have a 1/3 chance of getting the prize? You have 2 doors left, one with a prize. The third door had nothing behind it, and should just be ignored. Maybe a picture might help? Door1 Door2 Door3 You pick door2 Host opens door1 Door1 is empty [door1] Door2 Door3 You now have 2 doors to pick from: Door2(your first choice) or door3 This means your first choice has a 1/2 chance of being correct. Why does the first door still count in the chances? Peter Greenwood --- In [email protected], "Stefan Pochmann" <[EMAIL PROTECTED]> wrote: > > Shelley already mentioned it, but I'd like to point it out more > clearly. I'll give you a new variant of the riddle that points out an > important detail that can easily be misunderstood, leading to > different results. > > ----- > > There are three doors, one hides a car. You pick a door. The host > opens another and there's nothing. You choose between the two closed > doors and get what's behind it. Should you stay or switch? > > ----- > > Variant 1: The host knows what's behind the doors and when he opens > one, he deliberately picks an empty one. > > Variant 2: The host does *not* know what's behind the doors and when > he randomly opens one, it just happens to be empty. > > ----- > > Variant 1 is the original riddle with 2/3 probability getting the car > if you switch. Variant 2 is the new one I propose. What's your answer > for it? > > Cheers! > Stefan > SPONSORED LINKS Jigsaw puzzle game Free puzzle inlay games Educational game and puzzle Word puzzle game Kid puzzle game Puzzle games --------------------------------- YAHOO! GROUPS LINKS Visit your group "speedsolvingrubikscube" on the web. To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. --------------------------------- --------------------------------- Yahoo! doce lar. Faça do Yahoo! sua homepage. [Non-text portions of this message have been removed] ------------------------ Yahoo! Groups Sponsor --------------------~--> Get fast access to your favorite Yahoo! Groups. Make Yahoo! your home page http://us.click.yahoo.com/dpRU5A/wUILAA/yQLSAA/MXMplB/TM --------------------------------------------------------------------~-> Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/speedsolvingrubikscube/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
