BGonline.org Forums

100 islanders logic puzzle

Posted By: Gregg Cattanach
Date: Friday, 28 August 2009, at 12:14 p.m.

In Response To: 100 islanders logic puzzle (joe freedman)

Yes, they do look at each other. Part of the puzzle IS that EVERY islander knows exactly how many blue-eyed people he sees. Each sees 9 or 10. The problem is they don't have knowledge of their own eye color (the fact that exactly 10 DO have blue-eyes is not known at the beginning.)

It is the cascade of logical assumptions based on no one committing suicide on days 1-10 that ultimately forces each of the blue-eyed islanders to know their own eye color.

Messages In This Thread

• 100 islanders logic puzzle
  bob koca -- Friday, 21 August 2009, at 4:45 a.m.
  • 100 islanders logic puzzle
    likesbg -- Friday, 21 August 2009, at 5:16 a.m.
    • 100 islanders logic puzzle
      stw672 -- Friday, 21 August 2009, at 6:28 a.m.
      • 100 islanders logic puzzle
        Havard Raddum -- Friday, 21 August 2009, at 6:36 a.m.
        • 100 islanders logic puzzle
          Elliott Winslow -- Monday, 21 September 2009, at 11:56 a.m.
          • 100 islanders logic puzzle
            Elliott Winslow -- Monday, 21 September 2009, at 11:58 a.m.
            • 100 islanders logic puzzle
              Stein Kulseth -- Monday, 21 September 2009, at 1:17 p.m.
              • 100 islanders logic puzzle
                Fabrice Liardet -- Monday, 21 September 2009, at 1:51 p.m.
  • 100 islanders logic puzzle
    Matt Cohn-Geier -- Friday, 21 August 2009, at 6:06 a.m.
  • 100 islanders logic puzzle
    Havard Raddum -- Friday, 21 August 2009, at 6:32 a.m.
    • 100 islanders logic puzzle
      stw672 -- Friday, 21 August 2009, at 6:39 a.m.
      • 100 islanders logic puzzle
        Fabrice Liardet -- Friday, 21 August 2009, at 7:23 a.m.
  • 100 islanders logic puzzle
    misja -- Friday, 21 August 2009, at 9:18 a.m.
    • 100 islanders logic puzzle
      Tom Keith -- Friday, 21 August 2009, at 1:30 p.m.
      • 100 islanders logic puzzle
        Gregg Cattanach -- Friday, 21 August 2009, at 2:13 p.m.
        • 100 islanders logic puzzle
          Gregg Cattanach -- Friday, 21 August 2009, at 2:16 p.m.
  • 100 islanders logic puzzle
    dc-ohio -- Friday, 21 August 2009, at 12:17 p.m.
  • 100 islanders logic puzzle
    Jon -- Friday, 21 August 2009, at 1:07 p.m.
  • 100 islanders logic puzzle
    bob koca -- Friday, 21 August 2009, at 1:22 p.m.
    • 100 islanders logic puzzle
      Stein Kulseth -- Friday, 21 August 2009, at 2:25 p.m.
      • 100 islanders logic puzzle
        Bob Koca -- Friday, 21 August 2009, at 2:29 p.m.
        • 100 islanders logic puzzle
          misja -- Friday, 21 August 2009, at 2:46 p.m.
        • 100 islanders logic puzzle
          Fabrice Liardet -- Friday, 21 August 2009, at 3:05 p.m.
          • 100 islanders logic puzzle
            Stein Kulseth -- Friday, 21 August 2009, at 3:27 p.m.
        • 100 islanders logic puzzle
          Stein Kulseth -- Friday, 21 August 2009, at 3:13 p.m.
    • 100 islanders logic puzzle
      Tom Keith -- Tuesday, 25 August 2009, at 3:48 p.m.
  • 100 islanders logic puzzle
    Stein Kulseth -- Friday, 21 August 2009, at 2:13 p.m.
  • Don't read unless you want to know the answer...
    trichard -- Friday, 21 August 2009, at 3:02 p.m.
    • Don't read unless you want to know the answer...
      Fabrice Liardet -- Friday, 21 August 2009, at 3:07 p.m.
      • Don't read unless you want to know the answer...
        Rich Munitz -- Saturday, 22 August 2009, at 12:43 a.m.
        • Don't read unless you want to know the answer...
          Bob Koca -- Saturday, 22 August 2009, at 2:01 a.m.
          • Don't read unless you want to know the answer...
            Matt Cohn-Geier -- Saturday, 22 August 2009, at 2:09 a.m.
  • 100 islanders logic puzzle
    David -- Friday, 21 August 2009, at 3:21 p.m.
  • Something Wrong with Puzzle?
    David -- Friday, 21 August 2009, at 4:10 p.m.
    • Something Wrong with Puzzle?
      Fabrice Liardet -- Friday, 21 August 2009, at 5:13 p.m.
  • 100 islanders logic puzzle
    Christian Munk-Christensen -- Friday, 21 August 2009, at 4:56 p.m.
    • 100 islanders logic puzzle
      Gregg Cattanach -- Friday, 21 August 2009, at 5:40 p.m.
      • 100 islanders logic puzzle - what about a silent oracle?
        Gregg Cattanach -- Friday, 21 August 2009, at 5:46 p.m.
        • 100 islanders logic puzzle - what about a silent oracle?
          Steve Mellen -- Friday, 21 August 2009, at 6:15 p.m.
          • What happens after three?
            David -- Friday, 21 August 2009, at 6:41 p.m.
            • What happens after three?
              Gregg Cattanach -- Friday, 21 August 2009, at 6:51 p.m.
            • What happens after three?
              Steve Mellen -- Friday, 21 August 2009, at 7:25 p.m.
          • 100 islanders logic puzzle - what about a silent oracle?
            Ian Shaw -- Monday, 24 August 2009, at 1:00 p.m.
            • 100 islanders logic puzzle - what about a silent oracle?
              Tom Keith -- Monday, 24 August 2009, at 3:59 p.m.
              • 100 islanders logic puzzle - what about a silent oracle?
                Ian Shaw -- Tuesday, 25 August 2009, at 2:09 p.m.
        • 100 islanders logic puzzle - what about a silent oracle?
          Walfinho -- Friday, 21 August 2009, at 6:21 p.m.
      • 100 islanders logic puzzle
        Stein Kulseth -- Monday, 24 August 2009, at 9:45 a.m.
  • 100 islanders logic puzzle
    Jake Jacobs -- Saturday, 22 August 2009, at 2:10 a.m.
  • the really smart guy
    garyo -- Saturday, 22 August 2009, at 4:26 p.m.
  • 100 islanders logic puzzle
    Christian Munk-Christensen -- Monday, 24 August 2009, at 8:29 p.m.
  • 100 islanders logic puzzle
    Joe Russell -- Thursday, 27 August 2009, at 2:11 a.m.
    • 100 islanders logic puzzle
      Gregg Cattanach -- Thursday, 27 August 2009, at 12:25 p.m.
      • 100 islanders logic puzzle
        joe freedman -- Thursday, 27 August 2009, at 6:09 p.m.
        • 100 islanders logic puzzle
          Gregg Cattanach -- Friday, 28 August 2009, at 12:14 p.m.
      • 100 islanders logic puzzle
        Joe Russell -- Friday, 28 August 2009, at 12:51 p.m.