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| From | "BartC" <bc@freeuk.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Toughest Probability Question |
| Date | 2011-12-13 19:52 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <jc8aef$s10$1@dont-email.me> (permalink) |
| References | <9cb0f967-18d1-410c-9074-f4d84858d9af@u10g2000prl.googlegroups.com><4EE69C7E.12EB@mindspring.com><slrnjedm5u.2as3.usenet-nospam@guild.seebs.net><h2rde7tob4ibdd18an0opmflg3f4gqf8pk@4ax.com><slrnjee4qh.2irh.usenet-nospam@guild.seebs.net><jc7kqo$egv$1@dont-email.me> <ln39co8gyw.fsf@nuthaus.mib.org> |
"Keith Thompson" <kst-u@mib.org> wrote in message news:ln39co8gyw.fsf@nuthaus.mib.org... > "BartC" <bc@freeuk.com> writes: >> "Seebs" <usenet-nospam@seebs.net> wrote in message >> news:slrnjee4qh.2irh.usenet-nospam@guild.seebs.net... >>> On 2011-12-13, Geoff <geoff@invalid.invalid> wrote: >> >>>> The probability of AT LEAST two of them having the same birthday is >>>> greater than 50% if the number of people is at least 23. >>> >>> Read my post again, please. Not the part where I point out that the >>> problem >>> as stated *does not* specify that the distribution is at all random. >> >> And read the OP's post again: >> >> "before you can be certain that there is a greater than 50/50 chance" >> >> and note the word "chance". With 23 people, the chance IS greater than >> 50%, for certain. What is not for certain is that any two of those >> people WILL have the same birthday. > > An annual gathering of the No Two Birthdays Alike club, which has > 366 members (and lives up to its name), satisfies the conditions > stated in the problem and results in a 0 probability that at least > two of them have the same birthday. That's true. But it doesn't say anything about what kind of people are in the room, therefore we can't speculate. The probability of just over 50%, for 23 people people, means that's what you might expect when you examine large numbers of such gatherings; half the time, a birthday will be shared. Other times, in the case of your annual gathering for example, it won't be. If you had to place a bet, in the absence of any extra knowledge, the odds would have to be about even. -- Bartc
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Re: Toughest Probability Question pete <pfiland@mindspring.com> - 2011-12-12 19:29 -0500
Re: Toughest Probability Question Seebs <usenet-nospam@seebs.net> - 2011-12-13 04:46 +0000
Re: Toughest Probability Question Geoff <geoff@invalid.invalid> - 2011-12-12 22:19 -0800
Re: Toughest Probability Question Seebs <usenet-nospam@seebs.net> - 2011-12-13 09:19 +0000
Re: Toughest Probability Question "BartC" <bc@freeuk.com> - 2011-12-13 13:43 +0000
Re: Toughest Probability Question Keith Thompson <kst-u@mib.org> - 2011-12-13 10:27 -0800
Re: Toughest Probability Question "BartC" <bc@freeuk.com> - 2011-12-13 19:52 +0000
Re: Toughest Probability Question Seebs <usenet-nospam@seebs.net> - 2011-12-13 20:06 +0000
Re: Toughest Probability Question Keith Thompson <kst-u@mib.org> - 2011-12-13 12:14 -0800
Re: Toughest Probability Question "BartC" <bc@freeuk.com> - 2011-12-13 23:34 +0000
Re: Toughest Probability Question Seebs <usenet-nospam@seebs.net> - 2011-12-14 00:24 +0000
Re: Toughest Probability Question Seebs <usenet-nospam@seebs.net> - 2011-12-13 19:27 +0000
Re: Toughest Probability Question "BartC" <bc@freeuk.com> - 2011-12-13 23:56 +0000
Re: Toughest Probability Question Seebs <usenet-nospam@seebs.net> - 2011-12-14 00:24 +0000
Re: Toughest Probability Question "BartC" <bc@freeuk.com> - 2011-12-14 12:12 +0000
Re: Toughest Probability Question Seebs <usenet-nospam@seebs.net> - 2011-12-14 17:47 +0000
Re: Toughest Probability Question gordonb.qunma@burditt.org (Gordon Burditt) - 2011-12-15 08:22 -0600
Re: Toughest Probability Question Robert Wessel <robertwessel2@yahoo.com> - 2011-12-15 14:41 -0600
Re: Toughest Probability Question superpollo <superpollo@tznvy.pbz> - 2011-12-15 19:14 +0100
Re: Toughest Probability Question Keith Thompson <kst-u@mib.org> - 2011-12-14 13:12 -0800
Re: Toughest Probability Question Willem <willem@toad.stack.nl> - 2011-12-14 21:53 +0000
Re: Toughest Probability Question "BartC" <bc@freeuk.com> - 2011-12-14 22:35 +0000
Re: Toughest Probability Question Willem <willem@toad.stack.nl> - 2011-12-15 09:07 +0000
Re: Toughest Probability Question Geoff <geoff@invalid.invalid> - 2011-12-15 02:07 -0800
Re: Toughest Probability Question Keith Thompson <kst-u@mib.org> - 2011-12-15 12:13 -0800
Re: Toughest Probability Question Geoff <geoff@invalid.invalid> - 2011-12-15 13:03 -0800
Re: Toughest Probability Question Seebs <usenet-nospam@seebs.net> - 2011-12-15 21:36 +0000
Re: Toughest Probability Question Geoff <geoff@invalid.invalid> - 2011-12-13 16:35 -0800
Re: Toughest Probability Question Seebs <usenet-nospam@seebs.net> - 2011-12-14 01:20 +0000
Re: Toughest Probability Question Keith Thompson <kst-u@mib.org> - 2011-12-13 16:44 -0800
Re: Toughest Probability Question Seebs <usenet-nospam@seebs.net> - 2011-12-14 01:20 +0000
Re: Toughest Probability Question James Dow Allen <jdallen2000@yahoo.com> - 2011-12-15 02:33 -0800
Re: Toughest Probability Question gwowen <gwowen@gmail.com> - 2011-12-15 05:38 -0800
Re: Toughest Probability Question Thad Smith <ThadSmith@acm.org> - 2011-12-18 23:34 -0700
Re: Toughest Probability Question Bill Reid <hormelfree@gmail.com> - 2011-12-14 07:07 -0800
Re: Toughest Probability Question Kaz Kylheku <kaz@kylheku.com> - 2011-12-13 06:55 +0000
Re: Toughest Probability Question Seebs <usenet-nospam@seebs.net> - 2011-12-13 09:19 +0000
Re: Toughest Probability Question pete <pfiland@mindspring.com> - 2011-12-13 12:15 -0500
Re: Toughest Probability Question pete <pfiland@mindspring.com> - 2011-12-13 13:20 -0500
Re: Toughest Probability Question Peter Nilsson <airia@acay.com.au> - 2011-12-13 18:15 -0800
Re: Toughest Probability Question pete <pfiland@mindspring.com> - 2011-12-13 21:52 -0500
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