Can You Solve 'The Hardest Logic Puzzle In The World'?

MadFruit · 13 Oct 2014 at 09:07

lsg1r said:
as I said the answer on the site is not logical, therefore it can't be right

You can keep the rolleyes. You said nothing would change, which is wrong. Now you're saying the answer on the site is wrong and not logical, I suspect (although I haven't read it) it is both logical and correct. Please, do keep pushing your point though, you clearly have infallible logic yourself.

MadFruit · 13 Oct 2014 at 09:12

lsg1r said:
and you're missing a fine detail, the same as the original site did. They have to find out that the individual dragon has green eyes, a very specific detail. The human did not say ALL of them have green eyes therefore by logic it means that 1 or more may not have green eyes. Because logic is based on facts rather than theories they would never be able to confirm said details about their own eyes because like I said they don't talk about it and they have no mirrors (they clearly ignored water/glass etc....). They've known for ages that 99 others have green eyes but nothing has happened because no one has told the others they specifically have green eyes meaning each dragon does not know that they to have green eyes.

If and I mean if the dragons took a leap of faith, which they wouldn't do as they're logical, then they could change on the first night. The logic would be that statistically speaking if 99 out 100 have green eyes then the odds are that all of them have green eyes and they'd all change on the first night. However they wouldn't do this because of the facts presented to them.

Now you're just making yourself look stupid, you should probably stop there.

lsg1r · 13 Oct 2014 at 09:15

MadFruit said:
Now you're just making yourself look stupid, you should probably stop there.

you clearly don't understand logic, logic is all about facts and accurate information, not assumptions. EVERYTHING you've argued over relies on assumptions not facts. Either that or you can't understand the original question posed... it really is quite a simple logic puzzle.

I have read the answer on the site by the way... something you should go and read perhaps....

MooMoo444 · 13 Oct 2014 at 09:19

I like that carpark one. The best brain teasers are the ones that have you kicking yourself over the simplicity.

Bennie-Mac · 13 Oct 2014 at 09:20

L8

Now where is my nobel prize?

[FnG]magnolia · 13 Oct 2014 at 09:22

You sunk my battleship Bennie :mad:

MadFruit · 13 Oct 2014 at 09:26

lsg1r said:
you clearly don't understand logic, logic is all about facts and accurate information, not assumptions. EVERYTHING you've argued over relies on assumptions not facts. Either that or you can't understand the original question posed... it really is quite a simple logic puzzle.

I have read the answer on the site by the way... something you should go and read perhaps....

Logic is the reasoning and thus deduction of facts from other facts. I made no assumptions. I assure you, you are failing to grasp the logic, you seem determined not to read and understand. But don't worry about it, it is tricky and not everyone can grasp it.

glenimp617 · 13 Oct 2014 at 09:34

Regarding the dragon one

I don't think any dragon changes. In order for a dragon to change, they have to realise they themselves have green eyes. The human simply said, one of them had green eyes.

Each dragon knows the others have green eyes, but not themselves. They could assume they had pink and yellow spot coloured eyes.

Unless they all decide to talk about it, and tell each other that they have green eyes, how are they going to find out?

Surely the dragon on the next day sees nobody has changed and thinks to himself "well, they havent changed because they havent realise themselves.....but i aint gonna say anything lol"

Randomface74 · 13 Oct 2014 at 09:34

dragon puzzle is dumb because the dragons have known for ages that all other dragons have green eyes.

lsg1r · 13 Oct 2014 at 09:35

MadFruit said:
Logic is the reasoning and thus deduction of facts from other facts. I made no assumptions. I assure you, you are failing to grasp the logic, you seem determined not to read and understand. But don't worry about it, it is tricky and not everyone can grasp it.

really... I'm the one who isn't understanding the logic question

From the original question it states the 100 dragons haven't seen a human for many centuries...that would make them over 100 days old by the way.

The answer proposed by both you and the original site say that their logic would make them all turn into sparrows after 100 days once they have been told at least one of them has green eyes. Now without information about if they're colour blind, we'll have to assume they are not (the site did the same). Therefore logically speaking they would already know that 99 others have green eyes.

So how come they're centuries old, if they were logical as the question/answer implies they would have done that in the first 100 days not after centuries... meaning there would be no dragons for the human to meet. Therefore the answer proposed by you and the site can't be right.

Simply put the dragons weren't told anything new by the human.

glenimp617 · 13 Oct 2014 at 09:39

lsg1r said:
really... I'm the one who isn't understanding the logic question

From the original question it states the 100 dragons haven't seen a human for many centuries...that would make them over 100 days old by the way.

The answer proposed by both you and the original site say that their logic would make them all turn into sparrows after 100 days once they have been told at least one of them has green eyes. Now without information about if they're colour blind, we'll have to assume they are not (the site did the same). Therefore logically speaking they would already know that 99 others have green eyes.

So how come they're centuries old, if they were logical as the question/answer implies they would have done that in the first 100 days not after centuries... meaning there would be no dragons for the human to meet. Therefore the answer proposed by you and the site can't be right.

Simply put the dragons weren't told anything new by the human.

I was just about to say the same thing

Eurofighter · 13 Oct 2014 at 09:45

Don't do drugs.

Bennie-Mac · 13 Oct 2014 at 09:47

Dragons are colourblind.

glenimp617 · 13 Oct 2014 at 09:51

ok, after two coffees I agree that on the 100th day, all dragons will turn

The humans comment was the catalyst to mark the end day of the equation. Yes they all knew the dragons already had green eyes, but the humans remark set a baseline in time so the dragons could calculate (they were very logical) after 100 days they must have green eyes as well.

MadFruit · 13 Oct 2014 at 10:04

lsg1r said:
really... I'm the one who isn't understanding the logic question

From the original question it states the 100 dragons haven't seen a human for many centuries...that would make them over 100 days old by the way.

The answer proposed by both you and the original site say that their logic would make them all turn into sparrows after 100 days once they have been told at least one of them has green eyes. Now without information about if they're colour blind, we'll have to assume they are not (the site did the same). Therefore logically speaking they would already know that 99 others have green eyes.

So how come they're centuries old, if they were logical as the question/answer implies they would have done that in the first 100 days not after centuries... meaning there would be no dragons for the human to meet. Therefore the answer proposed by you and the site can't be right.

Simply put the dragons weren't told anything new by the human.

I'll give you, this is a tricky concept to understand (and to explain) but as I said in my first post...

MadFruit said:
The key to the human telling them all something they already know, is it gives a hard reset point at which the chain reaction can start... not really sure how better to phrase this. But without this, they can't know that every other dragon is waiting for the green-eyed ones to turn into sparrows.

If even one dragon did not hear this statement by the human, nothing would change, but the fact they were all there, all heard this, and that they all have infallible logic (remember, this is a logic puzzle, not a real scenario, we don't have to add 'assumptions that they're not colour blind' in). At this exact moment, every dragon knows that every other dragon heard this statement and will have come to the same conclusion. I can see 99 green pairs of eyes. If everyone else can see 98 pairs of green eyes, then they will change into sparrows on the 99th night, and then I do not have green eyes. If every other dragon is still about on the 99th day, then they too can see 99 pairs of green eyes, which means I have green eyes. Thus I must become a sparrow tomorrow... the 100th night.

Before this, there would be now way of knowing that any other dragon was waiting for any other dragon to turn. The comment the human made was critical to starting this process.

If you're still struggling, reduce the puzzle down to just 5, it's the same reasoning but is easier to follow through in your head.

glenimp617 · 13 Oct 2014 at 10:05

^ agreed!

lsg1r · 13 Oct 2014 at 10:48

MadFruit said:
text

Still doesn't work for me, I'll stick with my answer (s).

The answer assumes that the dragons want to know the answer to whether they have green eyes, they do after all only have to relinquish their powers if they discover they have green eyes, it's not taken from them.

Like I said earlier logically it is better to be a dragon than a sparrow so by the same thinking it's better not to know the answer. This can be ascertained by the fact that they don't discuss the topic of eye colour and have no mirrors....ie they don't want to change into a sparrow.

Greboth · 13 Oct 2014 at 10:58

lsg1r said:
Still doesn't work for me, I'll stick with my answer (s).

The answer assumes that the dragons want to know the answer to whether they have green eyes, they do after all only have to relinquish their powers if they discover they have green eyes, it's not taken from them.

Like I said earlier logically it is better to be a dragon than a sparrow so by the same thinking it's better not to know the answer. This can be ascertained by the fact that they don't discuss the topic of eye colour and have no mirrors....ie they don't want to change into a sparrow.

Agreed it is better not to know but the problem is for the dragons (and the solution to the puzzle) is that once they get to day 100 and none have changed then they all know they all (including themselves) have green eyes. Day 1 - 99 they can ask themselves 'Do I have green eyes' the answer is 'I don't know but I can see 99 of dragons with green eyes'. The fact none change on day 99 is because they can all see 99 dragons with green eyes so none know it is them, on day 100 the only logical conclusion is they themselves must also have green eyes.

MadFruit · 13 Oct 2014 at 11:01

This is a logic problem written in a story like prose in order to make it easier to follow and maybe fun to do. All the facts you need are in the question, if it doesn't mention it, it is irrelevant, stop applying "real world" considerations into a pure logic puzzle. One dragon isn't colour blind, one isn't selfish, another isn't blind. Adding any consideration outside the initial problem posed are missing the point. I feel like you're just making excuses now to avoid recognising the answer :\

cheesyboy · 13 Oct 2014 at 11:28

I still struggle to see how any of the individual dragons can come to the certain conclusion that they have green eyes.

We know they all have green eyes, but the dragons only know that at least one has green eyes, and that all the other dragons have the same colour eyes.

With 2 dragons, it would work. An individual would see a green-eyed-dragon and, knowing one or more of them must have green eyes, would know that if the other dragon doesn't turn into a sparrow (since he too can see the one green-eyed dragon), then the individual would assume that he himself must also have green eyes.

I don't see how that works with 3, or more, dragons. An individual would see 2 green-eyed-dragons, and would know that each of those two would see the other green eyed dragon. Neither would be expected to turn into a sparrow since they can all see the prescribed "at least one" green-eyed dragon and would, therefore, have no compulsion to assume they, themselves, are green-eyed.