WIN! Any woman that would give a list of 10 potential birthdates rather than being forthcoming about it is not worth my time.
Posted on 04/16/2015 9:29:47 AM PDT by QT3.14
One word problem from a Singaporean school exam briefly became the talk of the Internet last weekend....[Snip]... The puzzle went viral across the country, with people ranging from perplexed adults to eager teenagers grappling with the simple question: "So when is Cheryl's birthday?"
(Excerpt) Read more at theatlantic.com ...
Uh she told them both the month and day... it says so.
WIN! Any woman that would give a list of 10 potential birthdates rather than being forthcoming about it is not worth my time.
> On the basis of Albert’s statement that Bernard cannot know the answer, you can rule out any month with a unique day; because if Bernard were holding [May] 19 or [June] 18 he could know the Birthday without any information from Albert.
Albert was given the month, Bernard was given the day.
Albert who only knows the month announces that he knows that Bernard who only knows the day can not know the date. This tells Bernard that the day is not unique. Which rules out unique days - NOT the month those days are in.
Here’s how I came up with July 16th.
1) Albert knows that Bernard doesn’t know—which is saying the day of the month is not unique. Which means Albert wasn’t told “May” or “June”, because those months have unique days (18 & 19), thus they would have been possible for Bernard to know. Thus, just Albert’s statement narrows the birth month down to July & August.
2) Bernard went from not knowing the date to knowing the date. That rules out the day being 14, since Bernard would not know if Albert was told July or August. So Bernard was told 15, 16, or 17. This narrows the possibilities to July 16, August 15, or August 17.
3) Now Albert knows the date too. If Albert had been told August, he still would not know if it’s August 15 or August 17. That means it must be July 16.
However, to think this is 5th grade level in Singapore is amazing!
Don;t feel bad of you did not get the right answer.
Here is something that will cheer you up:
http://lawyer.tickld.com/x/irs-accuses-this-man-of-hiding-money-his-response-is-genius
I’m a little fuzzy on what the ambiguity is...
how is the 14th reconciled ?
The NYTimes thinks it is.
doh ! nevermind
This was given to fifth graders?
You have to eliminate June altogether, because if it was June, the only possible date that could be used was the 17th, as 18th would have let Bernard know immediately, without needing the month (only one 18th in the set of dates - remember, she told both of them the possible ten dates), since Albert knew Bernard didn't know at first, but then did, that has to eliminate May and June together, since May also had a unique date.
#@#$!
I think it was initially reported as such, but it was actually middle-schoolers...
doh ! nevermind
July 16
I don’t know about the rest of you, but as soon as the b!tch made it a math problem, I left.
You're not using part of what you know. You are not using the fact that Albert knows the month.
Albert knows that Bernard cannot know the answer without his help. That means he knows Bernard is not holding any date in May or June. How can that be? Only if Albert is Holding July or August.
Here's another way of looking at it:
Suppose, to the contrary, that Albert is holding June. Then he knows that Bernard has one of the days in June. Therefore, he CANNOT claim Bernard can't know the birthday without his help -- because Bernard might then be holding one of the unique days. We arrive at a contradiction. Therefore, Albert cannot be holding June.
The proof for May is identical. Assume, again to get a contradiction, that Albert is holding May. He can no longer make a definitive statement that Bernard cannot answer the question without him, because Bernard might very well be holding the unique day that occurs in May. Therefore Albert cannot be holding May, either.
So that leaves all the dates in July and August.
At that point, Bernies says...I now know. Therefore Al concludes that it must be a single day and that leaves only July 16, Aug 15, and Aug 17 as possibilities.
When Al announces that he now knows the answer, that means the answer must be the last remaining single month (because he only knows the month) otherwise, he would not know the answer.
June 17th.
It’s a logic problem.
Nope, not August 17th.
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