Singapore logic question

[Bishop82 61]

Can you solve it without looking up the answer?

 

http://www.theguardian.com/science/alexs-adventures-in-numberland/2015/apr/13/can-you-solve-the-singapore-primary-maths-question-that-went-viral

[nobody 2,037]

I'm thinking July 16th.

 

If Albert knows Bernard doesn't know the date, that means he wasn't told May or June since 18 or 19 would allow Bernard to know right away.

 

Bernard realizes this, so now he can apply the date he knows to only July and august. The fact that he knows rules out the 14th, so now we have July 16, august 15, or August 17. The fact that Albert now knows as well as bernard means it must be July 16th since if he was told the month was august he still wouldn't know.

[IGotWorms 3,310]

I have no idea how to work that out because I fockin suck at math, but I'm guessing it is June 18 or May 19 since those numbers don't repeat in any other month?

[Bishop82 61]

I'm thinking July 16th.

 

If Albert knows Bernard doesn't know the date, that means he wasn't told May or June since 18 or 19 would allow Bernard to know right away.

 

Bernard realizes this, so now he can apply the date he knows to only July and august. The fact that he knows rules out the 14th, so now we have July 16, august 15, or August 17. The fact that Albert now knows as well as bernard means it must be July 16th since if he was told the month was august he still wouldn't know.

[Djgb13 2,338]

I quit math after college. Only thing I like to do is add, subtract, multiply, or divide. Anything else I'm done messing with. No more "using statistics to test a hypothesis" or "using Pythagorean theorem" to find the answer.

[Voltaire 4,557]

I'm thinking July 16th.

 

If Albert knows Bernard doesn't know the date, that means he wasn't told May or June since 18 or 19 would allow Bernard to know right away.

 

Bernard realizes this, so now he can apply the date he knows to only July and august. The fact that he knows rules out the 14th, so now we have July 16, august 15, or August 17. The fact that Albert now knows as well as bernard means it must be July 16th since if he was told the month was august he still wouldn't know.

Well done. This is beautiful. I couldn't figure it out. I was stuck between May 19 and June 18 but couldn't see a shred of difference between either. I thought the "at first I didn't know" was a throw away line, instead it was the key to everything. Albert must have looked it up in school records or something.

[rholio 339]

I got to ____ __ pretty quickly. Neither guy tells the other what they know, and both figure out what it is. So, it's a month with 2 dates given, meaning ____ or ____. You also need a date that's not listed in ___ or ______, for both to figure it out.

 

____ __ matches both criteria. Hopefully, it's correct.

[OldMaid 1,838]

This really isn't a math question. It's a logic puzzle.

[rholio 339]

This really isn't a math question. It's a logic puzzle.

Exactly.

[IGotWorms 3,310]

This really isn't a math question. It's a logic puzzle.

This particular type of logic is remarkably similar to math. If you're good at one you are going to be good at the other.

 

Which is why I suck at it. Focking hated the logic games section of the LSAT as well.

[FeelingMN 273]

Only thing Albert and Bernard need to figure out is this b!tch plays mind games and will undoubtedly manipulate one into killing the other. Stay away guys.

 

[NorthernVike 2,080]

It made the tab crash on my phone.

[TimmySmith 2,782]

I am thinking august 17. It's the only date that you can lock in on.