I just got an email about voting for the top ten puzzles on here. I scanned over the options and ended up rereading " It's a great puzzle, but I think I've found a flaw.
When the Guru proclaims that he sees someone with blue eyes all that that tells the logicians is that everyone now knows there is at least one person with blue eyes. However, everyone already knows that as soon as they arrive on the island. Since everyone sees at least two people with blue eyes, everyone knows that everyone else sees at least one person with blue eyes. So the guru's statement is unnecessary, and if the subjects were actually perfect logicians then all the blue eyed people would leave on the 100th night of being on the island. The brown eyed people would too, because the same logic applies to them.
That wasn't explained the best, but if you understand the current solution to the problem you should be able to see how it would work without the guru's statement. Everyone has all of the information his statement gives right from day one. It would work for any number of blue eyed people, as long as there were at least three (the blue people need to see at least two other blue people to know that everyone sees at least one blue person).
Question
Guest
Hi everyone,
I just got an email about voting for the top ten puzzles on here. I scanned over the options and ended up rereading " It's a great puzzle, but I think I've found a flaw.
When the Guru proclaims that he sees someone with blue eyes all that that tells the logicians is that everyone now knows there is at least one person with blue eyes. However, everyone already knows that as soon as they arrive on the island. Since everyone sees at least two people with blue eyes, everyone knows that everyone else sees at least one person with blue eyes. So the guru's statement is unnecessary, and if the subjects were actually perfect logicians then all the blue eyed people would leave on the 100th night of being on the island. The brown eyed people would too, because the same logic applies to them.
That wasn't explained the best, but if you understand the current solution to the problem you should be able to see how it would work without the guru's statement. Everyone has all of the information his statement gives right from day one. It would work for any number of blue eyed people, as long as there were at least three (the blue people need to see at least two other blue people to know that everyone sees at least one blue person).
Any thoughts?
Alex
Link to comment
Share on other sites
2 answers to this question
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.