## Insane "Logic"

Philosophical, mathematical and computational logic, linguistics, formal argument, game theory, fallacies, paradoxes, puzzles and other related issues.

### Insane "Logic"

I find this to be insane. If it was worded more precisely then I could've worked it out. As it stands the language presented is so obscure that I would call it impossible to solve with any certainty.

note: You have to assume that one overhears the information given to the other, yet this overhearing is only one way? Bernard is capable of overhearing what is said, but Albert is not?

If I am wrong please explain why.

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### Re: Insane "Logic"

BadgerJelly » January 5th, 2018, 3:15 pm wrote:https://www.nytimes.com/2015/04/15/science/answer-to-the-singapore-math-problem-cheryl-birthday.html

I find this to be insane. If it was worded more precisely then I could've worked it out. As it stands the language presented is so obscure that I would call it impossible to solve with any certainty.

note: You have to assume that one overhears the information given to the other, yet this overhearing is only one way? Bernard is capable of overhearing what is said, but Albert is not?

If I am wrong please explain why.

It seems straightforward to me.

The one did not hear the information given to the other.

But each hears the statement made by the other and makes inferences from that.

B can infer from A's statement that A was told July or august.

B can infer from A's statement that A was told the 16th.

Therefore the 'answer' is July 16.

A_Seagull
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### Re: Insane "Logic"

Seagull -

No, that doesn't add up.

All that B can infer is a month was given to A. That is all. B can only work with the information B has (the Day.) Now, if A or B had over heard, which they didn't, it would be possible.

B cannot infer July or August unless they had been told the day was 14 ... so no, I don't see how this works at all. I am guessing there is a BIG error that is being missed here by one of us.

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### Re: Insane "Logic"

Okay. I'll call the times T1, T2, T3. As in:

At T1: Albert says that doesn't know when Cheryl's birthday is, but he knows Bernard doesn't know either.
At T2: Bernard agrees that he didn't know at T1 - but now, having heard what Albert said at T1, he says he knows.
At T3: Having heard what Bernard said at T2, now Albert knows too.

I'm not confident I've made it sound any less confusing, but I know what I mean, which I suppose is a start of sorts. Anyway: At T1 Albert can be sure it isn't May 19 or June 18. If it were, Bernard would know (because there is only one 19 and only one 18 on the list). The only way Albert can be sure of that is if he wasn't told May or June at all.

So now, at T2, Bernard can tell that Albert was told July or August. If he can use that information to eliminate all but one possibility, he must have been told the number "16".

So at T3, having discovered that Bernard was able to get it purely from that, Albert knows that Bernard was told the number 16. And remember that Albert already knows the month.

I don't know if that makes it clearer, but basically that's why A_Seagull is right. The puzzle doesn't explicitly say that Albert and Bernard are having a conversation, which I think is what threw Badger off. What I haven't figured out yet is why anybody would want to be friends with a pain in the ass like Cheryl.

Lomax

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### Re: Insane "Logic"

Thanks Lomax :)

To put it another way, the solution of July 16 is the only answer for which the statements by A and B are consistent with the 'logic' of the question. (One does have to assume that A & B are adequately good at logic and that they are not telling porkies.)

A_Seagull
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### Re: Insane "Logic"

I get the July and August part. I understand that Albert tells Bernard it is not May or June.

From there I don't see how Bernard can infer ... ah! Got it! hahaha! The way it is worded really threw me off. Yeah, obvious now.

Thanks

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### Re: Insane "Logic"

BadgerJelly » February 16th, 2018, 2:41 am wrote:I get the July and August part. I understand that Albert tells Bernard it is not May or June.

From there I don't see how Bernard can infer ... ah! Got it! hahaha! The way it is worded really threw me off. Yeah, obvious now.

Thanks

:) LOL

A_Seagull
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