I humbly admit defeat at the hand of Delphi. I should have paid closer attention to the sample apps (like running them). I think you explanation is good Alister but than what would I know :)
Rob Martin Software Engineer phone 03 377 0495 fax 03 377 0496 web www.chreos.com ----- Original Message ----- From: "Alister Christie" <[EMAIL PROTECTED]> To: "NZ Borland Developers Group - Delphi List" <[EMAIL PROTECTED]> Sent: Thursday, August 05, 2004 3:18 PM Subject: Re: [DUG] Welcome back problem > I thought I had a good explination > > Here is my table again > A: G G C > B: G C G > C: C G G > > A: represents Goat behind doors 1 & 2 and Car behind Door 3 > > Lets continue to assume that we still always pick door number 1 > > A: We've chosen a goat (however we don't know this). The presenter > will now tell us that there is a goat behind door 2. What happens if we > stay or swap? > Stay - Goat > Swap - Car > > B: Still chosen a goat, the presenter shows us that there is a goat > behind door number 3. And again here is what happens if we stay or swap. > Stay - Goat > Swap - Car > > C: Got the car this time, the presenter shows that there is a goat > behind door 2 (or 3) > Stay - Car > Swap - Goat > > So if we stay we get Goat, Goat, Car, thus 1 out of 3 times we get the car. > > If we swap we get Car, Car, Goat - 2 out of 3 times we get the car. > > The same arguments apply if we initially chose door 2 or door 3. > > I hope this explination makes things clearer. I think the main > confusion is from trying to assign probabilities. If I've missed > something and am wrong then will somebody explain my confusion in > language simple enough so that I can understand it ;-) > > However I think that the test applications also show that the answer is > correct even if my reasoning is wrong. > > Alister > > > Paul M - ProSouth wrote: > > Ok, if he opens door 2 to reveal the goat, we now know that option B (GCG) > > is incorrect, leaving: > > > > A: G G C > > C: C G G > > > > Again, a 50/50 scenario. > > > > Regards, > > > > Paul Matthews > > ProSouth Technology Solutions > > Phone: +64 3 470 1321 > > DDI: +64 3 470 1324 > > 0800 PROSOUTH (0800 776 768) > > 249 Cumberland Street, Dunedin, New Zealand > > Visit us at www.prosouth.co.nz > > > > ----- Original Message ----- > > From: "Stacey Verner" <[EMAIL PROTECTED]> > > To: "NZ Borland Developers Group - Delphi List" <[EMAIL PROTECTED]> > > Sent: Thursday, August 05, 2004 2:11 PM > > Subject: RE: [DUG] Welcome back problem > > > > > > > >>We aren't assuming that he opens door 3. He will open a door with a > >>goat, which in case A is door 2. > >> > >>Stacey > >> > >> > >>>-----Original Message----- > >>>From: [EMAIL PROTECTED] > >>>[mailto:[EMAIL PROTECTED] On Behalf Of Paul M - ProSouth > >>>Sent: Thursday, 5 August 2004 14:03 > >>>To: NZ Borland Developers Group - Delphi List > >>>Subject: Re: [DUG] Welcome back problem > >>> > >>> > >>>What you are ignoring is the additional information. > >>> > >>>Using your matrix, the host opens door 3 to reveal a goat. > >>>This now removes Option A, G G C, as being a possibility, leaving: > >>> > >>>B: G C G > >>>C: C G G > >>> > >>>There is now a 50% chance that the car is behind door 1 or 2. > >>> > >>>Regards, > >>> > >>>Paul Matthews > >>>ProSouth Technology Solutions > >>>Phone: +64 3 470 1321 > >>>DDI: +64 3 470 1324 > >>>0800 PROSOUTH (0800 776 768) > >>>249 Cumberland Street, Dunedin, New Zealand > >>>Visit us at www.prosouth.co.nz > >>> > >>>----- Original Message ----- > >>>From: "Alister Christie" <[EMAIL PROTECTED]> > >>>To: "NZ Borland Developers Group - Delphi List" <[EMAIL PROTECTED]> > >>>Sent: Thursday, August 05, 2004 1:36 PM > >>>Subject: Re: [DUG] Welcome back problem > >>> > >>> > >>> > >>>>There are 3 possible arrangements > >>>> > >>>>A: G G C > >>>>B: G C G > >>>>C: C G G > >>>> > >>>>if we assume that we choose door number 1 each time > >>>> > >>>>in both A & B we have choosen incorrectly and switching > >>> > >>>will give us > >>> > >>>>the correct answer (presuming the presenter always reveals a goat) > >>>> > >>>>In C we have choosen correctly and if we switch we loose. > >>>> > >>>>So 2 out of 3 times if we switch we win, so I think > >>> > >>>switching is our > >>> > >>>>best bet. > >>>> > >>>>Alister > >>>>_______________________________________________ > >>>>Delphi mailing list > >>>>[EMAIL PROTECTED] http://ns3.123.co.nz/mailman/listinfo/delphi > >>>> > >>>> > >>> > >>>_______________________________________________ > >>>Delphi mailing list > >>>[EMAIL PROTECTED] > >>>http://ns3.123.co.nz/mailman/listinfo/delphi > >>> > >> > >>_______________________________________________ > >>Delphi mailing list > >>[EMAIL PROTECTED] > >>http://ns3.123.co.nz/mailman/listinfo/delphi > >> > >> > > > > > > _______________________________________________ > > Delphi mailing list > > [EMAIL PROTECTED] > > http://ns3.123.co.nz/mailman/listinfo/delphi > > > > > _______________________________________________ > Delphi mailing list > [EMAIL PROTECTED] > http://ns3.123.co.nz/mailman/listinfo/delphi > _______________________________________________ Delphi mailing list [EMAIL PROTECTED] http://ns3.123.co.nz/mailman/listinfo/delphi
