I don't get it. If I was one of the infected monks and I saw nine others with dots on their head for nine consecutive days, how would that make me realize I'm infected? For all I know, there are only nine afflicted monks. That's not enough information for me to assume I'm infected and commit suicide on the tenth day.
Jaan gave the more precise explanation. Case 1: 1 monk has dot Each monk sees 99 other monks 99 monks see 98 with no red dot, and 1 with red dot 1 monk sees 99 no red dot He knows it's him. He sees no one else with red dot - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Case 2: 2 monks with red dot 98 monks see 97 with no red dot, 2 with red dot 2 monks see 98 with no red dot, 1 with red dot Both of these 2 monks know that in Case 1 the red dot monk they see would have killed himself. Why didn't the guy with red dot that I see kill himself if he saw 99 no dots last night? He must have seen another red dot. I don't see any other red dot but his. The red dot he saw must have been mine - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - No monk is ever certain that he does not have a red dot, until the suicides start. All the monks are aware of Case 1. All the monks are equally aware of Case 2. Since they are all aware of Case 2, knowing that two red dot monks would have both killed themselves after night #2, it follows that if they see two dots again on night #3, that Case #2 was not the answer. If there are three red dots, each one with red dot will see two other red dots. Each one will conclude that he has a third dot himself, since Case 1 and Case 2 did not eliminate the two other dots The equation continues as Jaan stated N = red dots, X = number of nights N = X
For anybody who still can't get the monk riddle; "No amount of observations of white swans can allow the inference that all swans are white, BUT the observation of a single black swan is sufficient to refute that conclusion" ~HUME~ If you can understand the above -- then you will realize why all 10monks suddenly knew they were the mark on the 10th night... If you can understand that, it wil go a long way toward understanding why traders such as Niedrhoffer and LTCM blew up... That riddle has a lot to do with the game we play and our condition in general. We cannot make the inference that there is not a 10th monk with the dot, because we might be it. This is exactly why I said that the answer was self-inferential in nature and it would always be a little "fuzzy" to my logical/rational left side of my brain. I never could solve that damn Epicurus Paradox, but I 'get' it...
so because YOU don't get it, i'm an idiot huh, goldenarm? what a jerkoff. the question you must answer is "how do YOU know if YOU have a dot"? if you see ONE guy with a dot, and he DOESN'T kill himself, guess who he is seeing a dot on? YOU. he doesn't kill himself because he can't see HIS OWN dot, he sees YOURS. so when he doesn't kill himself, you REALISE that the ONLY person he could POSSIBLY be seeing a dot on is YOU. because you can see EVERYBODY ELSE, and they DON'T have dots. YOU KNOW IT IS YOU.
It depends which question you are trying to answer. If you want the answer to how many socks do you need to cover the feet of 3 people, then you are correct. Six socks is the solution.
Okay, so I'm beginning to see this twisted reasoning. Thanks hii, for the succinct explanation. My bad! Sorry danny, no hard feelings?
Good, and that's fine for you goldenarm but I still can't see how 10 dots, 3 pairs of socks and some white swans, proves to a monk that he must top himself. these riddles....honestly!! Edit: huh... AND a golden heart !!