Our server costs ~$56 per month to run. Please consider donating or becoming a Patron to help keep the site running. Help us gain new members by following us on Twitter and liking our page on Facebook!
Current time: December 19, 2024, 2:22 am

Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Probability question: names in hats
#18
RE: Probability question: names in hats
(March 14, 2016 at 11:17 am)robvalue Wrote: That was the very first answer I came up with when I tried this Smile Sadly, it's wrong.

You're on the right track, but the probability for the second person depends on whether or not the first guy took his name already. If he took it, his probability is 8/9 again. If it didn't get taken, it's 7/8. Similarly, each pick will depend on whether his own one has been taken.

I can't get my head around how you account for all the combinations as they can all have different probabilities.

Are you sure?  I think it only makes sense to calculate the probability for the second person as 7/8 since there are only 8 names remaining after the first person removed one of the names other than his own.  The second person is only drawing from a hat with nine names in it and he too is unable to keep his own.  So his probability of choosing a name after the first person has drawn and kept a name other than person ten's should be 7/8 I think.
Reply



Messages In This Thread
Probability question: names in hats - by robvalue - March 14, 2016 at 5:45 am
RE: Probability question: names in hats - by robvalue - March 14, 2016 at 6:06 am
RE: Probability question: names in hats - by Mr.wizard - March 14, 2016 at 6:58 am
RE: Probability question: names in hats - by robvalue - March 14, 2016 at 7:03 am
RE: Probability question: names in hats - by Mr.wizard - March 14, 2016 at 7:08 am
RE: Probability question: names in hats - by ignoramus - March 14, 2016 at 7:03 am
RE: Probability question: names in hats - by Whateverist - March 14, 2016 at 11:18 am
RE: Probability question: names in hats - by ignoramus - March 14, 2016 at 7:19 am
RE: Probability question: names in hats - by robvalue - March 14, 2016 at 7:47 am
RE: Probability question: names in hats - by Aractus - March 14, 2016 at 8:13 am
RE: Probability question: names in hats - by Aractus - March 15, 2016 at 12:26 am
RE: Probability question: names in hats - by robvalue - March 14, 2016 at 8:29 am
RE: Probability question: names in hats - by robvalue - March 14, 2016 at 11:02 am
RE: Probability question: names in hats - by robvalue - March 14, 2016 at 11:12 am
RE: Probability question: names in hats - by Whateverist - March 14, 2016 at 11:59 pm
RE: Probability question: names in hats - by Whateverist - March 14, 2016 at 11:13 am
RE: Probability question: names in hats - by robvalue - March 14, 2016 at 11:17 am
RE: Probability question: names in hats - by Whateverist - March 14, 2016 at 11:22 am
RE: Probability question: names in hats - by robvalue - March 14, 2016 at 11:25 am
RE: Probability question: names in hats - by Whateverist - March 14, 2016 at 11:42 am
RE: Probability question: names in hats - by robvalue - March 14, 2016 at 1:50 pm
RE: Probability question: names in hats - by robvalue - March 14, 2016 at 11:45 am
RE: Probability question: names in hats - by Whateverist - March 14, 2016 at 12:40 pm
RE: Probability question: names in hats - by brewer - March 14, 2016 at 1:05 pm
RE: Probability question: names in hats - by Chas - March 14, 2016 at 1:54 pm
RE: Probability question: names in hats - by robvalue - March 14, 2016 at 2:00 pm
RE: Probability question: names in hats - by Chas - March 14, 2016 at 3:04 pm
RE: Probability question: names in hats - by Chas - March 14, 2016 at 11:17 pm
RE: Probability question: names in hats - by robvalue - March 14, 2016 at 2:05 pm
RE: Probability question: names in hats - by robvalue - March 14, 2016 at 2:09 pm
RE: Probability question: names in hats - by Whateverist - March 14, 2016 at 9:24 pm
RE: Probability question: names in hats - by Chas - March 14, 2016 at 11:48 pm
RE: Probability question: names in hats - by ignoramus - March 14, 2016 at 11:31 pm
RE: Probability question: names in hats - by Chas - March 14, 2016 at 11:47 pm
RE: Probability question: names in hats - by Whateverist - March 14, 2016 at 11:51 pm
RE: Probability question: names in hats - by Silver - March 15, 2016 at 12:02 am
RE: Probability question: names in hats - by robvalue - March 15, 2016 at 3:06 am
RE: Probability question: names in hats - by Whateverist - March 15, 2016 at 11:23 am
RE: Probability question: names in hats - by robvalue - March 15, 2016 at 11:35 am
RE: Probability question: names in hats - by Whateverist - March 15, 2016 at 11:55 am
RE: Probability question: names in hats - by robvalue - March 15, 2016 at 12:00 pm
RE: Probability question: names in hats - by Whateverist - March 15, 2016 at 1:10 pm
RE: Probability question: names in hats - by Aractus - March 15, 2016 at 12:52 pm
RE: Probability question: names in hats - by Whateverist - March 15, 2016 at 1:23 pm
RE: Probability question: names in hats - by robvalue - March 15, 2016 at 12:56 pm
RE: Probability question: names in hats - by robvalue - March 15, 2016 at 1:19 pm
RE: Probability question: names in hats - by Whateverist - March 15, 2016 at 1:31 pm
RE: Probability question: names in hats - by robvalue - March 15, 2016 at 1:26 pm
RE: Probability question: names in hats - by robvalue - March 15, 2016 at 1:35 pm
RE: Probability question: names in hats - by robvalue - March 15, 2016 at 1:38 pm
RE: Probability question: names in hats - by robvalue - March 15, 2016 at 1:52 pm
RE: Probability question: names in hats - by Whateverist - March 15, 2016 at 5:34 pm
RE: Probability question: names in hats - by robvalue - March 16, 2016 at 2:44 am
RE: Probability question: names in hats - by Whateverist - March 16, 2016 at 3:06 am
RE: Probability question: names in hats - by robvalue - March 16, 2016 at 3:21 am
RE: Probability question: names in hats - by robvalue - March 16, 2016 at 4:21 am
RE: Probability question: names in hats - by ignoramus - March 16, 2016 at 4:52 am
RE: Probability question: names in hats - by robvalue - March 16, 2016 at 5:03 am
RE: Probability question: names in hats - by robvalue - March 16, 2016 at 5:54 am
RE: Probability question: names in hats - by Cyberman - March 16, 2016 at 7:50 am
RE: Probability question: names in hats - by robvalue - March 16, 2016 at 8:13 am
RE: Probability question: names in hats - by Whateverist - March 16, 2016 at 8:16 am
RE: Probability question: names in hats - by robvalue - March 16, 2016 at 8:19 am
RE: Probability question: names in hats - by emjay - March 17, 2016 at 10:38 am
RE: Probability question: names in hats - by Aractus - March 18, 2016 at 12:30 am
RE: Probability question: names in hats - by Whateverist - March 18, 2016 at 1:34 am
RE: Probability question: names in hats - by Aractus - March 18, 2016 at 1:44 am
RE: Probability question: names in hats - by robvalue - March 18, 2016 at 7:50 am
RE: Probability question: names in hats - by Whateverist - March 18, 2016 at 7:59 am
RE: Probability question: names in hats - by robvalue - March 18, 2016 at 8:22 am
RE: Probability question: names in hats - by robvalue - March 19, 2016 at 12:58 pm
RE: Probability question: names in hats - by robvalue - March 19, 2016 at 2:25 pm
RE: Probability question: names in hats - by emjay - March 19, 2016 at 6:39 pm

Possibly Related Threads...
Thread Author Replies Views Last Post
  What's the probability that 3 out of 23 people will share the same birthday? FlatAssembler 28 4610 February 16, 2022 at 12:15 am
Last Post: Paleophyte
  Frog probability Aractus 17 4379 April 22, 2016 at 9:16 pm
Last Post: Aractus
  The role of probability in solving the Monty Hall problem Excited Penguin 209 19679 March 15, 2016 at 4:30 am
Last Post: robvalue
  The probability of the accuracy of probability itself? Etc. Edwardo Piet 15 6912 February 9, 2009 at 1:54 pm
Last Post: chatpilot
  Evidence and probability go hand in hand? Edwardo Piet 13 6114 November 7, 2008 at 9:46 am
Last Post: Darwinian
  Probability and Evidence. Edwardo Piet 9 6179 October 15, 2008 at 2:15 pm
Last Post: josef rosenkranz



Users browsing this thread: 3 Guest(s)