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# Island Baal

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Island Baal - Back to the Logic Problems

There are people and strange monkeys on this island, and you can not tell who is who (Edit: untill you understand what they said - see below). They speak either only the truth or only lies.

Who are the following two guys?

A: B is a lying monkey. I am human.

B: A is telling the truth.

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Island Baal - solution

Conjunction used by A is true only if both parts are true. Under the assumption that B is an honest man, then A would be honest too (B says so) and so B would be a liar as A said, which would be a conflict. So B is a liar. And knowing that, B actually said that A is a liar, too. First statement of A is thus a lie and B is not a lying monkey. However, B is lying which means he is not a monkey. B is a lying man. The second statement of A indicates that A is a monkey – so A is a lying monkey.

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• 2 months later...

If A is a liar(which is the case here) then either first statement could be false or second statement could be false or both could be false. So your conclusion then A is lying monkey assumes that both statements are false and neglects the possibility of first statement being false and second being true. If later is the case, then A is a lying human.

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hey

sorry..i missed the part of hypothesis that they only tell all truths or all lies. Then the conclusion you've got is correct. Nice puzzle!

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• 2 weeks later...

Took a while. Good puzzle!

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• 3 weeks later...

I just wanna say that monkeys can't talk... so how can they lie? And surely you can tell from seeing them that the human was human and not monkey (unless being contacted via radio or something).

Sorry if I got some facts wrong, I just like being technical.

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• 4 weeks later...

First off, to account for not being able to know what species they are by simply looking at them you might be blind, they could be wearing costumes, you might be on the opposite sides of a wall, you could communicate via radio, as you suggested, or any number of other possibilities. But, anyway, I actually got this one in like 5 seconds (litterally) since I read almost all of the of the other puzzles here so I already knew basically what was gonna happen. It was a great puzzle though, keep 'em comin!

really good one

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• 3 months later...

Definitely a good one. It took me a second to realize they could both be lying.

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So wait, if you take out the monkey and human part it will look like this

A: B is a liar. I am telling the truth.

B: A is telling the truth.

And that means that it is a paradox because B is saying that A is telling the truth but if A is telling the truth, B is lying so that means A is lying and B is telling the truth and it's right back where it started right?

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• 3 weeks later...

Island Baal - Back to the Logic Problems

There are people and strange monkeys on this island, and you can not tell who is who. They speak either only the truth or only lies.

Who are the following two guys?

A: B is a lying monkey. I am human.

B: A is telling the truth.

IF B IS A LYING MONKEY THEN HE WOULD NOT SAY A IS TRUTHFUL....WHICH MEANS HE'S AGREEING THAT HE'S A LYING MONKEY.....CONTRADICTION!!!!!NOW IF A IS LYING THEN B IS A HUMAN AND HE HIMSELF IS A MONKEY...THIS IS AGAIN CONTRADICTION!!!!!

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Since they must only lie or only tell the truth, this is an impossible statement, a paradox.

Using your logic that A is a liar, when A says B is a lying monkey, then B must be a truthful human. Then B would be lying to say A is telling truth. No solution.

A correctly stated puzzle would be for A to say, "B is a truthful monkey. I am human."

Then, A is a lying monkey; and B is a lying human.

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Using your logic that A is a liar, when A says B is a lying monkey, then B must be a truthful human.

nope, if "B is a lying monkey" is a lie ... then the truth is that:

1. B is a truth telling monkey OR

2. B is a lying human (anything but monkey) OR

3. B is a truth telling human

... any of the 3 options can be true

eg. when you lie that you drank 2 beers last night, actually, you could still have had 1 (or 10)

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• 4 weeks later...

A is a Monkey and B is a Human.

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• 2 months later...

IF B is truth then they would both be humans becuase B says A is telling the truth so

B=liar/monkey

A=Human/truth

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this one comfuses me i dont get it o_O

Edited by i_love_brain_teasers
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My question is if A is a monkey, then how did he tell us that he is a man and b is a lying monkey in the first place? I think we have other problems here.

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I HATE MONKEYS!!! THIS ONE WAS REALLY GOOD THOUGH.

both liars ?

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• 2 weeks later...

They are both liars, hopefully.

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I am not a big fan of this one. The answer chooses to divide the statements. If the whole statement that A makes is a lie, then, it can be because of the first part of the statement where A says that B is a lying monkey, or like the answer assumes, due to both statements being a lie, or the first part can be the truth (which cannot be because of the statement of B) and the second part could be a lie. I think A could be a monkey or a human.

A says: B is monkey and B lies and A is human.

B says: A is telling the truth.

A lies of B is human, or if B tells the truth, or if A is not human.

The answer divides the first statement and concludes that B is a human and B lies, which is fine, but then goes on to say that A is a monkey because A lies. However, A is already lying because of the first part of the statement, therefore doesn't necessarily have to lie about the latter part. A is not lying about the part that B lies either.

If there was a point in the question that said that every sentence is a lie, then the answer would have worked.

t

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• 2 weeks later...

'puzzlers' is correct, its a paradox. Too much unchecked stuff on this site.

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'puzzlers' is correct, its a paradox. Too much unchecked stuff on this site.

refer to my post #12 and write where exactly I went wrong in my reasoning

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A: B is a lying monkey. I am human.

B: A is telling the truth.

Let me take a shot ...

A speaks.

B responds either with the truth or with a lie so the 2 cases are ...

CASE1: If B is truthful, then A is telling the truth about B being a liar. So it's a conflict.

CASE2: If B is lying, then by saying "A is telling the truth" he's saying A is lying. If A is, in fact, lying, then B is NOT a lying monkey and since he IS a liar, he has to be a lying man. So, B is a lying man.

Since A is now established as a liar, he must also be lying about being human. So, A is a lying monkey.

A is a lying monkey

B is a lying man

Maybe some confusion comes by assuming that if "lying monkey" is a lie, it means he is neither a liar nor a monkey. But that is not correct. In fact, if "lying monkey" is a lie, it could be a "lying man", a "truthful monkey", or a "truthful man".

Clear as mud.

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• 3 months later...

this was really simple...a is a lying monkey and b is aw lying human! great ethics guys.....

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• 1 month later...

They speak either only the truth or only lies.

A: B is a lying monkey. I am human.

B: A is telling the truth.

You said they speak either ONLY TRUTH or ONLY LIES. That means that they cannot speak some truths and some lies in a statement. You cannot pull apart lying and monkey, the logic does not work that way. If you ever take a math logic class in college, this is very important. Therefore the puzzle is a paradox! You would have to say A: B is lying OR a monkey. I am human. B: A is telling the truth.

Persons A & B

lying = X

Monkey = Y

Human = Z

A says

B = XY does equal BOTH lying AND monkey

A = Z does equal human

B says

A != x does not equal lying

But

B = XY does equal BOTH lying AND monkey

So

A = X does equal lying &

A != Z does not equal human

Then

B != XY does not equal BOTH monkey AND lying

So

A != X does not equal lying

and so on and so on........

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