When is Cheryl's birthday?

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KnowItAll
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I am still trying to figure out who Cheryl is
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Robbie
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sj-roc wrote:I suspect the problem was originally devised by an ESL person whose mother tongue lacks any forms of English-like past tense in its verbs, where tense is instead conveyed with use of adverbs (e.g., "I write a letter yesterday", "I write a letter today", "I write a letter tomorrow"). I understand that this is the case for languages like Mandarin; someone like Robbie would likely have a better handle on this matter. The problem was perhaps even first composed in said mother tongue. In some accounts of the problem statement, the phrase "just became" in the first line was rendered as "just become"
:wink:
I suppose a typical confusing issue for SE Asians and ESL learners is when it comes to tag questions and statements as most Asian languages respond to negation questions in a different way, using two good examples:

FACT: I am not an ethnic Korean.
Question asked to me: Aren't you Korean?
Correct English answer: No (meaning No, I'm not Korean. I'm Chinese.)
Asian language-formatted answer: Yes (meaning Yes, you are right in that I'm not Korean.)

FACT: My friend and I saw a movie together and neither of us liked that movie.
Statement by my friend: That was not a good movie.
Correct English response: No (meaning No, that was not a good movie.)
Asian language-formatted response: Yes (meaning Yes, I agree with you in that it was not a good movie.)

It's understandable how ESL find it confusing that inverse questions like Are you Korean? and Are you not Korean? yields the same answer in English.
I have indeed noticed this language pattern from some ESL Asians in their English! One could argue pedantically that the Asian rendering is in fact more correct, but the wide consensus on the conventions of the English language dictate otherwise.
There are several good examples with it comes to colloquial and slang English terms as well. For example, with the expression about how one does not care or is not too concerned about someone or a situation, these two terms are now identical:
I couldn't care less == I could care less


These kinds of word problems and puzzles are typical in technical interviews given to candidates to assess their creative and logical approach. Microsoft has a whole bunch of these puzzles and I wonder why this one stood out as viral more than others. I suppose it's because it sounds original.

That said....how about a more traditional one. See if you can solve this without trying to look it up.

A woman named Jane is walking around a movie theatre when she suddenly points to a lady in a movie poster and excitedly exclaims:

I do not have any siblings, but that woman's mommy is my mommy's daughter.

Who is the woman in the movie poster that Jane pointed to?
Hmmm... sounds like the woman on the poster is Jane's daughter. Let's call Jane's daughter Anne and Jane's mother Betty. Then:

(that woman's mommy) is (my mommy's daughter) = (Anne's mother) is (Betty's daughter), where (Anne's mother) is Jane herself. Considering (Betty's daughter) by itself, this can only be Jane since she self-proclaims having no siblings, so everything is consistent.
Bingo. It was my variation of the original riddle: Brothers and sisters I have none, but that man's father is my father's son.
Some may automatically think that the speaker is referring to him/herself.
sj-roc wrote:
Toppy Vann wrote:What is happening is that people are working this problem backwards from the solutions and the explanations I have read over and over are illogical.

What they say means it's this date is nuts.

This comes from Singapore where their primary language is not English so you have to cut some slack but only to a point.

Others keep coming to an alternate date.

To trick students with poorly worded questions is shameful. This type of wording in business would get you fired.
Some people might be working it backwards (I'm not even 100% sure what you mean by this) but that doesn't invalidate the correct solution that has widely circulated. As for the alternate date, that's coming from a different formulation of the problem — a different problem, really — from what was given.

Criticising the language is a bit of a red herring IMHO. I would think the students to whom the problem was assigned probably have the same Asian-formatting to their English (which Robbie described) as the person/people who set it. Besides, for all we know, the competition in which this problem appeared may have originally been conducted in their own language anyway, with this English version only circulating in English-language media after the fact, which would make the whole language issue moot. I don't think any participants in the competition were "tricked". And I'd be willing to bet a good handful of them even managed to figure it out, too.

At any rate, there are plenty of highly talented mathematicians in North America and elsewhere who speak English as their mother tongue. If the syntax of the problem wording had created any issues, or if the problem itself, worded even in precise Queen's English, were somehow flawed and ill-posed so as to have no true, valid solution, I think we would have heard about it by now from at least one of them.

There's another aspect of this problem that seems to have gotten lost in the acknowledgement of its difficulty level. And that is, as difficult as solving this problem might be, creating a problem like this is an even more difficult challenge.

To explain what I mean, forget for a moment you ever heard the original problem that started this thread and consider instead this different but related one:
Albert and Bernard just became friends with Cheryl, and they want to know when her birthday is. Cheryl gives them a list of 10 possible dates.

May 15, May 16, May 19

June 17, June 18

July 14, July 16

August 14, August 15, August 17

Her birthday is actually July 16. She then tells Albert and Bernard separately the month and the day of her birthday respectively.

Is it possible for Albert and Bernard to determine together when Cheryl's birthday is, without disclosing to each other in any way the partial information about it that they have been given?
This IMHO is a MUCH more difficult, open-ended problem that the original one. The answer to it is yes, and it would take the three statements given in the original one for each of them to arrive at the correct answer (as per the solution of the original problem) without either of them directly disclosing what that already know.

The person who CREATED the original problem essentially solved this far more difficult one.
To avoid any language translation issues, write the message in Chinese using unambiguous terms, and then see if most students come up with July 16 or August 17.
The author will need to create Chinese names for Albert, Bernard, and Cheryl.
Unlike say when comparing European languages there's a direct name for common English names, i.e. John = Jean = Johann = Juan, the Chinese rarely adopt Chinese names based out of common English names, i.e. 約翰.
祝加拿大加式足球聯賽不列颠哥伦比亚卑詩雄獅隊今年贏格雷杯冠軍。此外祝溫哥華加人隊贏總統獎座·卡雲斯·甘保杯·史丹利盃。還每年祝溫哥華白頭浪隊贏美國足球大联盟杯。不要忘記每年祝溫哥華巨人贏西部冰球聯盟冠軍。
改建後的卑詩體育館於二十十一年九月三十日重新對外開放,首場體育活動為同日舉行的加拿大足球聯賽賽事,由主場的卑詩雄獅隊以三十三比二十四擊敗愛民頓愛斯基摩人隊。
祝你龍年行大運。
恭喜西雅图海鹰直到第四十八屆超級盃最終四十三比八大勝曾拿下兩次超級盃冠軍的丹佛野馬拿下隊史第一個超級盃冠軍。
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sj-roc
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Toppy Vann wrote:I have yet to see a decent mathematician / educator give this question any kudos.
Also, further to my last response, here's a CNN article that contains a video of the solution, done by a tenured math prof at Georgia Tech. I doubt he would have even dignified the problem by solving it had he felt it was poorly devised. Also, he makes the grammar correction I noted in the early stages of this discussion, from "At first I don't know" to "At first I didn't know".

http://www.cnn.com/2015/04/15/living/fe ... oes-viral/

Here's an article about the math professor who set the problem as part of the competition. He acknowledges he's not the creator of it but it had already existed in other forms (for example, the coloured clothes scenario I gave is logically equivalent to it).

http://www.straitstimes.com/news/singap ... birthday-p
Meet the mathematics professor behind 'Cheryl's birthday' puzzle
Published on Apr 18, 2015 2:36 PM

By Chew Hui Min

SINGAPORE - The man behind the "Cheryl's birthday" viral poser is a mathematics professor from the National Institute of Education (NIE).

Dr Joseph Yeo Boon Wooi, who is in his 40s, is part of the panel for the Singapore and Asian Schools Math Olympiads (SASMO), the largest math competition here.

He helps set the questions each year for student "mathletes".

This year's competition took place on April 8. The puzzle in question was leaked, and subsequently posted on Facebook on April 11 by local TV presenter Kenneth Kong, who initially mistook it for a Primary 5 question.

Dr Yeo, a recipient of the prestigious Nanyang Excellence in Teaching Award in 2013 and first author of the New Syllabus Mathematics used in secondary schools, said he first chanced upon a Facebook post discussing the birthday logic problem on April 12.

But it did not ring a bell until he saw the photo of the question.

It has since been featured on international media such as The New York Times, The Guardian and the BBC, and was a top-trending story on US site Buzzfeed. On April 16, "Cheryl" even got her own cartoon on The New Yorker.

The Straits Times caught up with the media-shy math whiz and persuaded him to answer some questions about himself and how he came up with the viral hit that has confounded the world.

Dr Yeo's birthday, coincidentally (or not), falls on July 16 - the answer to the puzzle.

Q: How did you come up with the question "Cheryl's birthday"?

A: I set the question based on guidelines given by SASMO. This question, like all other questions we set, was vetted and approved by a panel of local and overseas experts from the SASMO Partners' League, which organises SASMO contests in their own countries. "Cheryl's birthday" is not a new logic problem. There are various versions which others have modified. I am not aware of the original source. I modified it by changing the names, dates and context or storyline.

Q: What do you think of the buzz it has generated?

A: I first saw someone on Facebook talking about the Cheryl's birthday logic problem on Sunday (April 12). It didn't ring a bell. Then I saw a photo of the question. I was like, "Heh! This looks familiar!" I still cannot believe that the question has gone viral.

Q: Which aspect of math do you specialise in?

A: I am a lecturer with the National Institute of Education. I specialise in training student teachers how to teach secondary school maths.

Q: How did you develop your interest in maths?

A: It just comes naturally to me. I enjoy solving maths and logic problems.
Part of the what made the problem go viral was that it was initially reported erroneously as a math problem to be solved by students at a much lower grade. Had it been correctly framed from the outset as a problem for elite, higher level students, it might never have captured peoples' imaginations in the way that it did.

Which headline sounds like better clickbait: "Asian children's math problem stumps adults" or "High-level math competition committee sets challenging problem for elite students"?

By the time this detail was clarified, it was too late to halt its momentum.
Sports can be a peculiar thing. When partaking in fiction, like a book or movie, we adopt a "Willing Suspension of Disbelief" for enjoyment's sake. There's a similar force at work in sports: "Willing Suspension of Rationality". If you doubt this, listen to any conversation between rival team fans. You even see it among fans of the same team. Fans argue over who's the better QB or goalie, and selectively cite stats that support their views while ignoring those that don't.
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sj-roc
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Toppy Vann wrote:...people are working this problem backwards from the solutions and the explanations I have read over and over are illogical.

... Others keep coming to an alternate date.
The committee that posed the problem has offered a statement on this alternative interpretation of the problem (as posted by Robbie) that makes the birthday Aug 17. Like I noted in another post, to have Bernard state from the outset that he doesn't know the birthday makes it a different problem. So the Aug 17 solution is disallowed and based on this communiqué, the committee concurs.

Image
Image

The above images were edited/excerpted from the following source, mainly for LB.com image size compliance reasons:
http://mothership.sg/2015/04/people-are ... y-its-not/
Sports can be a peculiar thing. When partaking in fiction, like a book or movie, we adopt a "Willing Suspension of Disbelief" for enjoyment's sake. There's a similar force at work in sports: "Willing Suspension of Rationality". If you doubt this, listen to any conversation between rival team fans. You even see it among fans of the same team. Fans argue over who's the better QB or goalie, and selectively cite stats that support their views while ignoring those that don't.
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Toppy Vann
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Typical Singaporean dogmatism. It still makes no sense to me how they explain it. Singapore logic lol.

Any decent prof that I know that dabbled in problems would state unequivocally that a problem must be clearly stated.

These clowns should teach some critical reasoning skills but the culture isn't predisposed that way.

How this "stretches" a students "analytical skills" is something that eludes Henry who can't understand the gray in his problem. His writing is crap.
"Ability without character will lose." - Marv Levy
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sj-roc
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Toppy Vann wrote:Typical Singaporean dogmatism. It still makes no sense to me how they explain it. Singapore logic lol.

Any decent prof that I know that dabbled in problems would state unequivocally that a problem must be clearly stated.

These clowns should teach some critical reasoning skills but the culture isn't predisposed that way.

How this "stretches" a students "analytical skills" is something that eludes Henry who can't understand the gray in his problem. His writing is crap.
LOL no offence but you seem pretty dogmatic about this yourself, Toppy. Not sure what they ever did to you.

The problem was reverently solved in a video on CNN by a tenured NA non-ESL math prof who offered no comment of any grey area or not being clearly stated. No prof of such standing is going to risk his professional reputation over something like this in such fashion if it wasn't sound. No one with any clout in the mathematical community has offered any public criticism of it. It was vetted by an international panel of experts. They even deigned to respond to confusion on the Aug 17 matter, even though the problem never should have been released to the public and the guilty party who initially did so may face discipline, because the same set of questions from which this problem originated was to be assigned to participants in another country.
The questions were set by a team of mathematics experts, including professors here [in Singapore] and overseas.

The same set of questions was also given to participants in 14 other countries, including Britain, Malaysia, Brunei and Uzbekistan. Mr Ong said that Cambodia has yet to run the competition, and will do so on May 4. The leaked question will be replaced.

He said that leaking the question is considered cheating, and the student who took and circulated the photo can be disqualified from the competition.
Even if the language wasn't precise Queen's English (it was close enough), the logical structure of the solution and of the statement of the problem itself is still rock solid.
Sports can be a peculiar thing. When partaking in fiction, like a book or movie, we adopt a "Willing Suspension of Disbelief" for enjoyment's sake. There's a similar force at work in sports: "Willing Suspension of Rationality". If you doubt this, listen to any conversation between rival team fans. You even see it among fans of the same team. Fans argue over who's the better QB or goalie, and selectively cite stats that support their views while ignoring those that don't.
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Toppy Vann
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My animosity is how stacked a deck they make the English language in Asia against locals in these countries.

I have seen them administering tests that native English speakers can't pass and then fire people for failing.

I saw a video too on CNN that is on the 'net and I have read a lot of comments where they say what I am saying and come up with two answers.

Oh they concede now that it could be read another way and get a different answer BUT they didn't back down.

How is this training critical thinkers who can look at issues and see both sides - something lacking in this part of Asia due to detriment of their people who have to take the lower jobs as a result. We'd not accept that in the west if we were the majority.

If you're going to say there is just one solution it shouldn't then be debatable based on the wording.

Dogmatic is what educators have become in parts of the world.

This Arkansas mom schooled the school board coming up with the same answer the rest of the world would get:

http://www.westernjournalism.com/arkans ... nightmare/
"Ability without character will lose." - Marv Levy
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Toppy Vann
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My animosity to the question was fueled by the alternate solution which is what I got and they reject as Singapore educators say we are wrong to read the first statement as a statement of fact - it's just a statement of knowledge.

Now this guy is clearest of all and his logic doesn't mysteriously eliminate May and June with little logic like others.

He goes thru the solutions and how Singapore rejects the most popular alternate solution



This other dude is very clear and I get it what he saying but the first ones I saw were shockingly poor explanations in rejecting the alternate solution. Do we need more rigid - just one solution thinkers - NO!!! That's just mental *beep*.



I'm a fan of Sir Ken Robinson in how schools and education kills creativity. I taught at BCIT for 13 years at night (OB and Management) until my work commitments were too great to keep it up. My number one problem was in making the students feel it was okay to speak out. Yes, the bold and loud will always speak but the others by the time they get to college age have learned that a wrong answer makes them look dumb so they keep quiet. Even those who took these classes after working a few years and had degrees.

I had to make every answer a right answer. Unless it was that one bold person (male or female) who you could say no to, I'd deliberately say when I asked questions during my attempt at Socratic dialogue presentations of the class materials - "that isn't what I was looking for but I want to come back to what you said." Then I'd come back to the wrong answer with a question or answer that made the person's point valid. No one had to fear being wrong as I wanted participation.

As to Ken Robinson and creativity here's his TED talk:



Transcript of one presentation that I fully subscribe to. Here in Asia this is lacking many times over to the detriment of locals who grasp for one solution only as that is how they've been taught. Learn by rote. Get one answer.

This needs the charts but the retest found lower scores with these kids as they got more education.

https://www.thersa.org/globalassets/pdf ... script.pdf
Divergent thinking isn't the same
thing as creativity. I define creativity as the
process of having original ideas that have value.
Divergent thinking isn't a synonym but it's an
essential capacity for creativity. It's the ability
to see lots of possible answers to a question, lots
of possible ways of interpreting a question to
think what Edward de Bono would probably call
laterally - to think not just in linear or convergent
ways. To seek multiple answers, not one.
So there are tests for this, I mean, one
kind of cod example would be people might be
asked to say how many uses can you think of
for a paper clip; one of those routine questions.
Most people might come up with ten or fifteen.
People who are good at this might come up
with 200. And they'd do that by saying, "Well
could the paperclip be 200 foot tall and made
out of foam rubber?" "Does it have to be a
paperclip as we know it, Jim?" Now they tested
this and they gave them to 1,500 people in a
book called
Break Point and Beyond
, and on
the protocol of the test if you scored above a
certain level you'd be considered to be a genius
at divergent thinking.
So my question to you is what
percentage of the people tested of the 1,500
scored at genius level for divergent thinking.
Now you need to know one more thing about
them - these were kindergarten children. So
what do you think? What percentage at genius
level? 80? 98%. Now the thing about this was
it was a longitudinal study, so they retested the
same children five years later aged 8 to 10.
What do you think? 50? They retested them
again five years later, ages 13 to 15. You can
see a trend here can't you?
"Ability without character will lose." - Marv Levy
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Robbie
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Reviving this thread in light of the fact that school is starting soon and math problem controversies have gone viral again.

http://www.msn.com/en-us/lifestyle/what ... ocid=ientp

Q: Use the repeated addition strategy to solve : 5 * 3
Incorrect: 5 + 5 + 5 = 15
Correct: 3 + 3 + 3 + 3 + 3 = 15

This never happened during my time in grade school. :roll:
祝加拿大加式足球聯賽不列颠哥伦比亚卑詩雄獅隊今年贏格雷杯冠軍。此外祝溫哥華加人隊贏總統獎座·卡雲斯·甘保杯·史丹利盃。還每年祝溫哥華白頭浪隊贏美國足球大联盟杯。不要忘記每年祝溫哥華巨人贏西部冰球聯盟冠軍。
改建後的卑詩體育館於二十十一年九月三十日重新對外開放,首場體育活動為同日舉行的加拿大足球聯賽賽事,由主場的卑詩雄獅隊以三十三比二十四擊敗愛民頓愛斯基摩人隊。
祝你龍年行大運。
恭喜西雅图海鹰直到第四十八屆超級盃最終四十三比八大勝曾拿下兩次超級盃冠軍的丹佛野馬拿下隊史第一個超級盃冠軍。
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