(No Cheating) When Is Cheryl's Birthday?

[+ MysticMenace]

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

 

Cheryl then tells Albert and Bernard separately the month and the day of her birthday respectively.

 

Albert: I don't know when Cheryl's birthday is, but I know that Bernard does not know too.

Bernard: At first I don't know when Cheryl's birthday is, but I know now.

Albert: Then I also know when Cheryl's birthday is.

 

So when is Cheryl's birthday?

[rvwnsd]

I don't care. Miss Thing is too high-maintenance.

[Guest]

July 16th.

[+ nycman]

Hate logic puzzles but strangely drawn to them.

 

The shitty English in this one reflects the fact that it was first posed as part

of the Singapore and Asian Schools Math Olympiad (SASMO) in 2015.

To me the unclear English makes this one unintentionally harder than

it really is.

 

Just to make you feel stupid.....it was written for 14 year olds.

 

Specifically, I would rewrite the line:

“Cheryl then tells Albert and Bernard separately the month and the day of her birthday respectively.”

 

To be:

“Cheryl (the obnoxious cunt) tells Albert the month of her birthday but not

the day, and she tells Bernard the day of her birthday but not the month”

 

Hope that helps.

 

I still hate logic puzzles.....have fun.....grin

[jjkrkwood]

I cant even remember when my own Birthday is ! And THEY didnt send me a Christmas card, so Fuck them........

[+ sync]

I have NEVER been able to solve logic puzzles, but I enjoy reading the solutions.

[Guest]

Well, of course the simplest thing for Albert and Bernard to do would be to just tell each other what they know. Barring that, the fact that Albert knew Bernard didn't know means the month couldn't have been May or June, because if the date were the 18th or 19th, Bernard would have known immediately without needing to know the month. At this point, Bernard has been informed that the month is either July or August. If it were the 14th, they still couldn't have figured it out, because it could have been either month. Also, if it were 8/15 or 8/17, Bernard couldn't have known the date, because it could have been either one. Only 7/16 worked out.

I used to be upset by people who would leave me birthday wishes on my birthday on Facebook, because it "outed" my birthday, which I consider private, and not for public knowledge. I therefore changed my birthday to 1/1/30, and dutifully got some birthday wishes on New Year's Day. "Remembering" my birthday because Facebook told you is not an act I cherish.

[+ BenjaminNicholas]

[+ Charlie]

Since she told Bernard the day, but May is the only month when 19 appears, and June is the only month in which the 18 appears, he would think it was May 19 or June 18. However, when Albert says he knows that Bernard does not know the full date, Bernard must realize that Albert knows it is not either of those dates. Therefore, it has to be July 16. Oh damn! Unicorn has beaten me to the answer before I could explain it!

[+ Charlie]

Here is another puzzle: one of the dates Cheryl has given is my spouse's birthday, and another is the birthday of one of the regular posters on this site. Figure that one out, Singapore adolescents!

[+ sync]

My baloon has been burst and trampled. I am as befuddled by the verbiage of the solution as I am by the verbiage of the problem. ?

[Phil_musc]

Since she told Bernard the day, but May is the only month when 19 appears, and June is the only month in which the 18 appears, he would think it was May 19 or June 18. However, when Albert says he knows that Bernard does not know the full date, Bernard must realize that Albert knows it is not either of those dates. Therefore, it has to be July 16. Oh damn! Unicorn has beaten me to the answer before I could explain it!

Doesn't this solution presuppose that Albert and Bernard are brilliant, logical thinkers and that they both really care to solve a problem put to them by some sort of high maintenance bitch who will probably prove to be more trouble than she is worth? I say Albert and Bernard should save themselves the hassle and settle on dating each other.

[+ MysticMenace]

Here is another puzzle: one of the dates Cheryl has given is my spouse's birthday, and another is the birthday of one of the regular posters on this site. Figure that one out, Singapore adolescents!

 

I am not a Singaporean adolescent, though I think I could still pass as one ? - but I'll take a stab -

• spouse's birthday - complete guess (8/14)
  
• regular posters - either lucky or buckguy (8/17)
  

[rvwnsd]

Here is another puzzle: one of the dates Cheryl has given is my spouse's birthday, and another is the birthday of one of the regular posters on this site. Figure that one out, Singapore adolescents!

I am not a Singaporean adolescent, though I think I could still pass as one ? - but I'll take a stab -

• spouse's birthday - complete guess (8/14)
  
• regular posters - either lucky or buckguy (8/17)
  

 

One of the HMB's birthday options is two days away from my birthday! I'd be lion if I said I don't want you to guess.

[+ MysticMenace]

One of the HMB's birthday options is two days away from my birthday! I'd be lion if I said I don't want you to guess.

 

well, sir, you'd still be a lion even if I guessed that the HMB's birthday option you were referring to is 8/14, 2 days away from your birthday on 8/12;)

[+ Oliver]

Here is another puzzle: one of the dates Cheryl has given is my spouse's birthday, and another is the birthday of one of the regular posters on this site. Figure that one out, Singapore adolescents!

Your spouse: July 14

[Guest]

Your spouse: July 14

[+ Charlie]

Your spouse: July 14

No, @JoeMendoza was correct, though I have no idea how he guessed it.

[+ MysticMenace]

No, @JoeMendoza was correct, though I have no idea how he guessed it.

 

Oh yay! It was not a complete guess, but I saw a post somewhere where you said your spouse's birthday is the same as the anniversary as when you met him for the first time, then another post mentioned said anniversary where it mentioned you'd be celebrating it 'a month from then' - unfortunately, that post was on July 24. but then I figured, it probably has to be August, and the wild guess was that the date probably ended in a 4. Lol. So much for logic.

[+ Charlie]

You remember the details in my posts??! Good grief!

[+ MysticMenace]

You remember the details in my posts??! Good grief!

 

Haha, since I can't really apply logic here like those Singaporean students, I went with what I could do - good 'ol research of old posts.