How'd they figure that? (logic puzzle)

[belliott4488]

or i know why they committed suicide is they had eyes. They can see each other' eye color. You should have posted that they are color-blinded, or mute

Or, better yet, you should have read the original statement of the puzzle more closely!

 

[country boy]

Okay, now how many days until the blue-eyes self-inflict?

 

[Oerg]

Okay, now how many days until the blue-eyes self-inflict?

They do not know the colour of their eyes as blue, all they know is that there are green eyed people on the island, and that their eye is of different colour. In other words, they do not know the word to decribe their eye colour.

 

[Oerg]

I still think its a rather funny puzzle, with a few flaws, with one of the major flaws in that

If say there were 2 green and 1 blue, on the first day of comtemplation at the town centre, if there wasnt any hesitation in all 3 to do a ritual suicide, then they would have known at that moment that the 2 greens were green in eye colour. Why don't they commit suicide then and there?

And if all of the greeny citizens were to think this way, all would commit suicide on the first day.

I think this puzzle can only be solved on the basis of many assumptions.

Perhaps it would be better to say it this way,

1. All citizens would gather at the towncentre every day to contemplate the colour of their eye for 5 minutes. After 5 minutes of contemplation, all citizens who know the colour of their eyes are to commit ritual suicide immediately and the rest of the citizens are to return to their daily chores right away and return to the town centre again the next day.

 

[country boy]

Okay, now how many days until the blue-eyes self-inflict?

They do not know the colour of their eyes as blue, all they know is that there are green eyed people on the island, and that their eye is of different colour. In other words, they do not know the word to decribe their eye colour.

I don't think they are language-challenged. They will know about colors and have names for them.

To see the symmetry between green and blue, start with 200 of each (or two of each).

Some of the difficulties talked about here could be solved by stating that the islanders don't know how many colors there are until Robinson Crusoe tells them "Hey, there are only green and blue eyes on this island!"

 

[Oerg]

I don't think they are language-challenged. They will know about colors and have names for them.

Thats the problem with this question, it leaves a lot of information to assumption

 

[belliott4488]

I still think its a rather funny puzzle, with a few flaws, with one of the major flaws in that

If say there were 2 green and 1 blue, on the first day of comtemplation at the town centre, if there wasnt any hesitation in all 3 to do a ritual suicide, then they would have known at that moment that the 2 greens were green in eye colour. Why don't they commit suicide then and there?

And if all of the greeny citizens were to think this way, all would commit suicide on the first day.

I think this puzzle can only be solved on the basis of many assumptions.

Perhaps it would be better to say it this way,

1. All citizens would gather at the towncentre every day to contemplate the colour of their eye for 5 minutes. After 5 minutes of contemplation, all citizens who know the colour of their eyes are to commit ritual suicide immediately and the rest of the citizens are to return to their daily chores right away and return to the town centre again the next day.

I'm not sure I'm following your reasoning. Are you suggesting that if the green guys commit suicide on a given day, then since the blue guys might then learn their own eye color they could also commit suicide, i.e. on the same day? I see how your suggested statement of the rule for meetings solves that, but I don't see how my original statement was not equivalent. The reason I said that they must silently contemplate for ten minutes and only after this period commit suicide was specifically to prevent this problem.

I also don't see why anyone would kill himself on Day 1 in your example; the stranger guy announced only that there were green-eyed people, of which there are two, right? So the green guys would each be hoping that the other green guy was the sole green guy. (Unless you're using the fact that the stranger used the plural, which I think is an unnecessary muddling of the problem - in this case just have him say something stupid like, "there are one or more green-eyed people on this island, although I am not specifying anything about the actual number." )

As for country boy's question about how many days till the blue-eyed guys kill themselves - as the problem was stated in the original post, they never should, since each one can hope that he's the one brown-eyed guy on the island. If the stranger had said, "there are some green, some blue, but no other color of eyes ..." then they'd do themselves in on the next day after the green-eyed guys.

 

[country boy]

As for country boy's question about how many days till the blue-eyed guys kill themselves - as the problem was stated in the original post, they never should, since each one can hope that he's the one brown-eyed guy on the island. If the stranger had said, "there are some green, some blue, but no other color of eyes ..." then they'd do themselves in on the next day after the green-eyed guys.

Actually, law 1 requires that "At noon every day, all 1000 citizens must gather... ." After the 200 die, it is not longer possible to comply. So, is everyone else off the hook?

 

[belliott4488]

Actually, law 1 requires that "At noon every day, all 1000 citizens must gather... ." After the 200 die, it is not longer possible to comply. So, is everyone else off the hook?

Oh, for goodness' sake ... of course the law wouldn't be tied to to a specific population. This is a logic puzzle, not a legal puzzle! You have to exert a little effort to get into the spirit of the problem.

Change that to "all citizens must gather ..."

 

[country boy]

Oh, for goodness' sake ... of course the law wouldn't be tied to to a specific population. This is a logic puzzle, not a legal puzzle! You have to exert a little effort to get into the spirit of the problem.

Change that to "all citizens must gather ..."

Sorry, I thought I was in the spirit. Wording is important in logic puzzles, but we can also have a little fun.

I've enjoyed your puzzle and the discussion. Have a nice holiday!

 

[belliott4488]

Sorry, I thought I was in the spirit. Wording is important in logic puzzles, but we can also have a little fun.

I've enjoyed your puzzle and the discussion. Have a nice holiday!

Thanks - enjoy your holiday as well. That's the best spirit to be in!

I think this puzzle is plenty challenging enough without injecting additional complications. People tend to ask questions like, "well, what if not all the citizens have the same IQ - they can't all reach the same conclusions!" True enough, if the point were to be discussing a real-world problem, but I'd almost rather just reduce this to a problem in pure logic or information theory - not that I'm really sure how to do that!