Eye colour problem...

Why would they assume the other blue eyed person would leave at all, if the sage didn't give the advice? It all comes back to that one blue eyed person situation. If nobody can assume that one blued eyed person who sees only brown eyed people will know that he has blue eyes (because the sage has told them he sees somebody with blue eyes) they can do bugger all.

Here's an xkcd page on the answer:

https://xkcd.com/solution.html

The questions he asks "that may force you to further explore the structure of the puzzle" are:

Randall Monroe wrote:What is the quantified piece of information that the Guru provides that each person did not already have?

Each person knows, from the beginning, that there are no less than 99 blue-eyed people on the island. How, then, is considering the 1 and 2-person cases relevant, if they can all rule them out immediately as possibilities?

Why do they have to wait 99 nights if, on the first 98 or so of these nights, they're simply verifying something that they already know?

I think I've got a grip on this now. Ready for the next one when you are, Jamie!

Paul wrote:

Jamie wrote:I think you're missing something Paul; and it's a something I'm pretty sure is there, I just don't know how to explain it. But let's consider this...

Why don't the any of the brown eyed people ever leave?

Also, if the sage didn't mention the colour blue; would any blue eyed person leave?

If not, why not?

They do,  they ALL leave. 

Colour is Irrelevant, imagine the same question but with brown being the stated colour,  same result,  they ALL leave.

Are you going to the expo? I'll explain it then!

Paul wrote:They do,  they ALL leave.

I don't think they do...

Any one brown eyed person, knows there are 99 other brown eyed people; but does not know he himself has brown eyes. For example, how would a brown eyed person know he has brown eyes, rather than yellow eyes?

Sam wrote:I think I've got a grip on this now. Ready for the next one when you are, Jamie!

I'm all out! I only knew those 2 off the top of my head. There's Cheryl's birthday; but I think everyone probably knows when that is...

If anyone else has a logic problem, go ahead...

In the version of the puzzle I remember there were only 2 possibilities, brown or blue, they just didn't know which. 

I don't think it works otherwise.

As I understood the puzzle (originally, I found it on the site Sam linked to), there are only 2 kinds of people on the island, blue and brown eyes. However; they don't know that. Each person can see a bunch of other people, some with blue, some with brown eyes. They don't have the knowledge that you, the observer has, that there are a 100 of each colour.

For example, Mr Peters, is one of our blue eyed residents on the island. He can see 100 people with brown eyes, and 99 people with blue eyes; however, he has no idea as to the colour of his own eyes. They could be pink for all he knows!

Hope that helps Paul.

It's possible I've made a mistake or overlooked something; but can't see. To my understanding, the brown eyed people are stuck on the island forever! The poor dears!

Jamie wrote:As I understood the puzzle (originally, I found it on the site Sam linked to), there are only 2 kinds of people on the island, blue and brown eyes. However; they don't know that. Each person can see a bunch of other people, some with blue, some with brown eyes. They don't have the knowledge that you, the observer has, that there are a 100 of each colour.

For example, Mr Peters, is one of our blue eyed residents on the island. He can see 100 people with brown eyes, and 99 people with blue eyes; however, he has no idea as to the colour of his own eyes. They could be pink for all he knows!

Hope that helps Paul.

It's possible I've made a mistake or overlooked something; but can't see. To my understanding, the brown eyed people are stuck on the island forever! The poor dears!

No help needed,  I'm fine  with my logic

That wasn't meant to sound as arrogant as it did, sorry.  

In your version of the puzzle, only the blue eyed people would leave after 100 days,  the brown eyed folk would be stuck there FOREVER! 

At least my version of the puzzle had a happy ending!

If everyone knows that there are only two eyes colours, would the hundred brown eyed people leave one night later?

Sam wrote:If everyone knows that there are only two eyes colours, would the hundred brown eyed people leave one night later?

No,  they'd leave the same day, following the same logic as the blues.

No-one leaves, picture the scene :
An arrogant paranoia quickly spreads and identifies those who do NOT have blue eyes. This faction rapidly becomes militant (realising they may never leave the island) and holds those with blue eyes hostage.
A sudden interest in ophthalmic surgery arises after the hostages arrange to donate (literally) an eye for an eye, with each donor pair meeting beforehand. Thus each pair of islanders knows the colour of their own remaining eye and the colour of the donated eye, opening an exit route for all concerned.
Poor operational hygiene such as befalls a remote island nation results in significant complications for the patients, including (but not limited to) infection and sight loss.
The community crumbles bemoaning the predicament they have found themselves in, they curse the damned sage and her witchery and vow to burn any outsider boat that may approach in the future.
The island community fades into myth, tales of the Cursed Tribe with Two-Toned Eyes haunts the dreams of generations to come.....


Sorry, I agree with Paul.

I think Paul is a spy.

I think we need a like feature on this forum

Kes wrote:I think we need a like feature on this forum

:thumbup:

Paul wrote:That wasn't meant to sound as arrogant as it did, sorry.

God no, you didn't come across that way at all!

Paul wrote:In your version of the puzzle, only the blue eyed people would leave after 100 days,  the brown eyed folk would be stuck there FOREVER! 

At least my version of the puzzle had a happy ending!

Yep, they do; the blue eye people get away; while the brown eye people stay forever, and rot, and get eaten by the maggots! :p