Cheryl's Birthday Puzzle || Brilliant Viral Puzzle on Facebook and WhatsApp
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- เผยแพร่เมื่อ 24 ม.ค. 2018
- Cheryl's birthday problem has been extrmeley viral on facebook and whatsapp since 2015 till date.
Albert and Bernard have just become 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 repsectively.
Albert : I don't know when cheryl's birthday is, But i know that Bernard doesn't know either.
Bernard : At first I didn't know when cheryl's bithday is, but I know now.
Albert : Then I also know when Cheryl's birthday is.
So when is cheryl's birthday ?
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Change the first statement to "I don't know, maybe Bernard knows"
Bernard: At first I didn't know, now I do.
Albert: June 17
If first statement is 'may be Bernard knows' then it is possible in all the four months. So your answer is wrong buddy😎
What if month is may ,ur re proved wrong
@NotMy RealName
Other than June 17 ,two more options left for Albert
May 15 and May 16
1. Bernard may know because there are UNIQUE Days in the given Month. Therefore the months are May and June.
2. Bernard didn't know at first, so it's not a date with UNIQUE Day. Therefore it's 15, 16 or 17.
3. Albert now knows because in the given Month there is only one date left (June 17). May would have two dates at this point, and he wouldn't have been sure of which yet otherwise.
Why did they remove may though ?
Considering the first statement:
Albert knows that Bernard doesn't know, but if Bernard knew it could have been may 19 or June 18, so Albert excluded these dates , but knowing that Bernard doesn't know, Albert still doesn't know , so we eliminate June 17 . But if we stick with may options neither of them could have known ! Because there are two options in this month and 2 dates of (16 and 15) ! So why did they eliminate may ?
I was stuck on that too. The difference for me was that the statement 'but I know Benard doesn't know either' - You have to interpret it based on what Albert knows and not what Bernard knows. Albert knows that both May and June have singleton dates that would allow Bernard to guess the outcome immediately - if Albert says 'but I know Bernard doesn't know either' it must be because Albert was told a Month for which there are no singleton dates (thus eliminating May and June). The difficulty you probably are having which was confounding me too is that I interpreted 'but I know Benard doesn't know either' as that the information was conveyed by Benard to Albert - if that is the case, then May would be back in play. Hope that helps.
@@IamMineOwn June is left with a singleton date not may
@@IamMineOwn can u plz tell why may 16 can't be a possible answer.
@@V7B817 'but I know Bernard doesn't know either' completely eliminates May and June.
Albert did not eliminate May. He KNEW it was July. Albert also knew that Bernard was given either 14 or 16, and that Bernard would not be able to conclude the month because these numbers were also options for some other months .
Bernard did eliminate May and June based on Albert's first sentence. According to what Albert said, none of the months with unique dates would be possible.
Brilliant explaination.
very nice and logical trick.....and bro your channel is my favorite one from all logical channels...:)
Thanks Adarsh... your comment is always precious to me and it really inspires me to make more and more videos :)
This was really awesome 👌
Wow! It is a wonderful puzzle I understood after watching this vedio more than 10 times
Awesome!
I loved your explanation! Thanks for the video! Can you do one for the muddy children puzzle?
Thanks Nancy... well, muddy children puzzle looks similar to blue eyes (or red dots) puzzle where 100 people are on island with no mirror(which I'm planning to post soon). I will certainly prepare the solution for muddy children with all 4 scenario. Thanks for the question. I'll look forward to get more questions from you :)
Thank you for replying! I'm trying to learn Dynamic Epistemic Logics, that's why I want to understand the muddy children puzzle, and that's what brought me to this video. Then I saw your video on prisoners and hats. I really enjoy your explanations.
Watching your videos have helped me improve my logical reasoning skills as a result of which I was easily able to solve this puzzle within 2 minutes on my own with the same logic that was explained in the video... Feeling blessed to have been a part of your channel... God bless you bro... Keep making more and more videos... 👍
That's great and interesting because by face you still look dumb.
@@kuls43 people who don't even dare put up their faces in dps shouldn't comment on others faces, I think!
Very interesting...
Man!🙏🙏👍you are awesome! I could not understand from the websites,but you explained it easily!👌👌😁.Thank you!
I got it!!!! Man it took 15 mins XD !! Super one tho :)
Good one on tricky...
Thanks Vinith :)
1. A can eliminate the entire months of May and June (because that's the only way he can logically say that B doesn't know either at first).
2. B now becomes aware of that same fact and both now know that the only possible candidates remaining are the entire months of July and August.
3. B now knows her birthday, which means that it can not be July 14th nor August 14th
.
4. A now knows her birthday, which means it has to be July 16th because that's the only remaining candidate month that holds a single date.
-Answer: July 16th
Best explanation that I have found so far for this question 👍
Over-complicated, check out mine from 12/12/2021
Woww excellent
A tricky one. Couldn't solve it and I also watched the video twice to understand the logic. Good work bro
Thanks Pragun for the appreciation :)
I have see all the videos But the video I like the most is cheryl's birthday riddle
I would prefer pursuing another woman than breaking my head with brick.
Why albert and bernard dont tell each other? Its easier..
Albert: hey the Month is July
Bernard: ya the date is 16th
Problem solved 😁😁
Great video
Great
How you come to your last conclution? Maybe Bernard knew when the birthday is with 15 or 17 day. So Albert couldn't know for sure is 16
Yes.. bernard still has other two options which ll not allow him to know the date exactly..
Bernard said he knew her birthday. That means it *wasn't* the option that gave him multiple choices.
But Albert KNOWS the month. If it was the month containing 15th or 17th (August), then Albert would not have said that he knows the answer now. But if the true month is July, then there's only one choice for that month, and thus Albert would know.
I think albert and bernard also love math
Very nice puzzle....
Thanks Areeb
U made impossible looking puzzle fairly possible 👍🏻
but there's May 15 or 16th, Bernard could have received May 15th or 16th
Ek tarfa hai bhai
Cheryl be playing typical mind games...😂
Tameez naam ki cheej hai ??
But how does Albert got the date
Though we consider his last statement right we able find the date
Awesome.......
I have watched many of your videos and i didnt understand a single. It is way too complicated.
For this problem you can refer to @Numberphile
There explanation is in more detail.
Sadly thinking logically is not for everyone
This can be looked at as a challenge to Albert, Bernard, and the audience, who have to work together to find Cheryl's birthday, but Albert is given a month, while Bernard a day, and the audience nothing. Albert and Bernard can only make three statements using " I don't know " or "I know Cheryl's birthday.
So Albert, after observing that only May (19 ) and June (18) have unique days 19 and 18, the first statement was, 'I don't know Cheryl's birthday, but I know Bernard doesn't know either,' which tells Bernard that Cheryl's birthday was not in May or June since Albert couldn't have made that statement if Bernard had received 18 or 19. In other words, her birthday was either in July or August. But May per se was not the most important month/date to be eliminated, specifically May 16, since Bernard got '16' from Cheryl and there were only two '16s, July 16 and May 16.
Therefore, GAME OVER for Bernard since ONLY July 16 was left. And so he knew her birthday was July 16.
So it is now Bernard's time to help Albert, so though Bernard knows her birthday is July 16, by saying aloud, ' I didn't know at first Cheryl's birthday, I now know' ELIMINATES one of the two Julys leaving just one as Bernard was observing/looking at July 14, July 16, August 14, August 15, and August 17 as just JULY from these FIVE dates had the number, '16, consequently, Bernard knew her birthday was July 16.
Albert was helped because he knew that Bernard could not have said ' I now know ' if he was given a '14' because there are both July 14 and August 14. This leaves just one July (in this case, July 16), and so Albert was able to find her birthday since he has a July, but now only ONE ONE ONE July was left, July 16 (It wouldn't matter if it was July 16 that was left or July 32 or July 100 as long there was just ONE ONE ONE JULY left Albert would have found out her birthday since she gave him the month of July
Time to help the audience, and Albert did so when he loudly said,' Then I didn't know Cheryl's birthday, but I know now ' after being left with July 16, August 15, and August 17. This tells the audience that Albert has 'July' or was given July since there was just ONE July from these three dates (July 16, August 15, and August 17), and so the audience concludes that her birthday is in July and hence Cheryl's birthday
is July 16. Game over for all three: Bernard, Albert, and finally, the audience (us)
In sum, Albert could not have gotten August from Cheryl and made the statement 'Then I now know' since there were two MORE Augusts, but just ONE July; after all, she cannot have two birthdays, August 15 and August 17. So we, too got to know her birthday was July 16, as Albert was given July.
Albert first helped Bernard by reducing the two '16s' (May 16 and July 16) to just one '16' (July 16), who in turn helped Albert by reducing two 'Julys' ( July 14 and July 16) to just one 'July '(July 16) who in turn helped the audience. And all three found out from these three statements made loudly 'I don't know, but I know Bernard doesn't either.. ', ' I didn't know before but now I know, and 'Then I now know. These three statements were the key to all three finding the solution: JULY 16.
Afterthought: The puzzle could have included 'June 16' to appear more complicated. However, June 16 would have been eliminated at the same time as May 16 with Albert's first statement, " I don't know Cheryl's birthday, but I know Bernard doesn't know her birthday either,
What if the day is 15 may. How can Albert eliminate may and June then?
Albert's first response would be, "I don't know but maybe Bernard knows" (Because 'May' could be May 19, Which Bernard 'would know'.
Since Bernard received '16' (or if any other day) his goal is to see one month with a 16 . So he doesn't want to see May 16, and July 16 together , instead he wanted to be left with either August 16 or May 16. It is fine if he only had May 16 left (then May 16 would be her birthday ) , but he cant have both May 16 and July 16. It is fine if he sees June 14, June 17, August 15 , May 18, or whatever other month as long as he is only left with ONE month with a 16.
So this is why Albert was so helpful to Bernard , when Albert said 'I don't know Cheryl's birthday but I know that Bernard doesn't either' since this eliminate all the dates with May and consequently eliminated May 16 leaving just ONE month with a 16 (July 16, July 14, August 14 , August 15 and August 17) and so Bernard was able to find her birthday.
So when Bernard then said " now I know' after Albert statement, this helped Albert to know Cheryl's birthday since it eliminated a July (in this case July 14) leaving only ONE July (in this case July 16)(remember Albert was left with July 16 , July 14, August 14 , August 15 and August 17, two Julys and three Augusts, but since August 14 and July 14 have the same day, Albert was able to conclude that August 14 and July 14 were not her birthday since Bernard could not have said ' I now know' and this in turn eliminated July 14, leaving just ONE July as while Bernard goal (as said above) is to only have ONE month with a 16,
Albert' goal is just to have ONE JULY LEFT whether it is July 14 or July 16 but not both.
So Albert is left with July 16 , August 15 and August 17. He is left with ONE July and two Augusts . it doesn't matter HOW MANY August he is left with as long as he is left with just ONE July it is Game over.
If he was left with just one August , such as from: August 16, July 15 , July 16 , July 17 (or whatever) then August the 16 would have been her birthday, since he would have been left with just ONE August (and three Julys or whatever amount of July would not matter).
So for both Albert and Bernard to get her birthday , they have to each end with just 'ONE'.
In Albert case, he needed to see just ONE month and for Bernard just ONE month with a '16' or whatever day he was given. So Bernard just want to eliminate all the months with a '16' EXCEPT for just ONE to get her birthday.
i liked your puzzles
The logic in this is flawed. Bernard will know the Birthday but Albert can not know. The key statement is Albert's "But I know Bernard does not know" This immediately tells Bernard it is not in May or June. If he were still unsure then the day he had been told would have been the 14th. But because he now knows the birthday he has been told the day is the 15th, 16th, or 17th. There is no way for Albert to then deduce the actual date. As a corollary, if Bernard had been told the day is the 18th or 19th. then he would have know immediately the month but poor Albert would still be in the dark. what is 0/0 => Cookie Monster is sad because he has no cookies, and you are sad because you have no friends.
Why would Albert think it is in August when he was given the month of July and told that the month he was given was the month of her birthday. So if he was told that her birthday was in July and only three dates left July 16 , August 15 and August 17, the answer has to be July 16. And if Albert said 'then I know now' then readers must know he has to have gotten July because he could not have known if had received August since there are two dates August 15 and August 17. Remember Albert was given the right month (and Bernard the correct day).
Devon Devon I at first thought the question was flawed. Now after reading ur comment, everything makes sense.
@@deewu3825 Thanks, I thought something was missing too until I look over it again
But how can albert say that he knows the bday date? He was left with three different dates right🤷
He was left with 2 months and he already knew the date
Good explanation but there is a mistake in this riddle. If the date is August 15 or August 17 then Albert could not confirm the date.
But he could. Yes, the fact that he could is essential enough for this puzzle to have an answer. The answer is found through the facts we've been given. That's how puzzles work, right?
Super
Thank you Myra 😊
Brilliant ... but I could not solve
Wow, a great problem!
Thanks Sara :)
Wow! July 16 is my birthday
@aamar It can be June-17 as well !
A say B doesn’t know because 17 is there in June and Aug . So this eliminates only 18/19 day not the entire month.
But once B says I know it could be only June -17
No.A will not be confident enough to say that B doesn't know the birthday date,if it was June.Because if B was told 18 he could find the date as June 18.Also according to A's first statement,if it was June 17 ,then B doesn't know the date(It means B has been told 17 but he is unsure whether it's June or August).So,A knows it is June and B is unsure of the month .This leaves A with the date 17 and A will know the answer.But this is contradictory to A's statement (A said" I don't know and B does not know either").Hope you understand.
I got the right answer in about 5 minutes ! Woohoo ! (ok, not a feat, but ok nonetheless)
An interesting thing is that my birthday also falls on the 16th of july ...lol
Veejay Xetri what’s your id number too... no reasons...
😍
How did you eliminate may and june
Knowing that the possible month are July and Aug ,Bernard can tell what day is the birthday if has numbers 15,16,17. So he knows. But this information elliminates for Albert only the option of 14. From what Bernard said Albert can't know exactly what day is the birthday.
I would like to correct myself.The only way for Albert knowing the exectly date after eliminating the 14th is a day in July.So July 16 is the answer.
Doesn't make sense to me... :( How does Bernard know it's not May 16th?
If it were may 16th, albert would've got the month as may but he was sure that bernard wouldn't know the bday , but if bernard knew the date to be 19th he would be damn sure that the b'day is on may19th as there is no other 19, hence we exclude out the possibility of the bday month being may.
@@yashshrivastava7316 if it is May 16, then also Albert can confidently say Bernard wouldn't know the answer, because 16 appears in two months..how can we rule out May..
atleast 17th June can be ruled out..if it were June, when Bernard doesn't answer, Albert can directly say it as 17th June
How these type questions are created..?🤔🤔
I think this problem can be made more complex and interesting if we assume that Cheryl told Bernard the day of the week on which she was born and not the date. Could someone coment please?
I'm going through all comments and just took a screenshot of yours... i must try this!
@@LOGICALLYYOURS
Thanks for the prompt response. In fact, I didn't think this thread was still alive. I stumbled upon this variation accidentally. I came across Cheryl's puzzle in my mother tongue, Malayalam and mistook the date for day. So I presumed the earliest date among the ten, May 15 to be a Tuesday (2020). Accordingly I got 2 Mondays, 2 Tuesdays, 2 Wednesdays, 2 Saturdays, 1 Sunday and 1 Friday. Naturally the day can't be Sunday or Friday. So two months having these days, June and August were eliminated. So I was left with July and May. The latter can't be the month as it has three dates and hence Albert can't be sure. So it's July 16, as July 14 is a Saturday; so is May 19. I think this should work out whatever day we presume May 15 to be. I just worked it out casually in response to a friend who forwarded it to me as a Corona pastime. I am not very sure if my logic is sound. Regards.
Exactly....
This is what i thought..
She told the day i.e. mon tue wed.....and so on...
Not the date of the month
I think, logic to remove May and June is illogical.
Suppose the logic is OK and I use it to solve a similar problem wherein there are 12 dates. All above 10 plus 20th July and 21st August. Now, 20 and 21 also appear once in the whole lot, like 18 and 19. Will you remove all 4 months and declare tha, Cheryl was never borne? She is "Ajanma"? Albert's statements only tell that the dates in the month told to him also appear elsewhere. Hence B does not know. That's all.
The very fact that B is silent means that the dates are not 18 and 19. We don't need A to yell out that B cannot solve.
Yes sir, i also think the same hope amar will reply
If 18 or 19 then Bernard would "know". In the first statement Albert said Bernard can't know. So May and June are eliminated.
Not able to understand
I came across this problem and have been trying to understand why you eliminate May 15 and 16. I read all the comments on multiple videos and I must be missing something.
I understand Albert knows the month, and Bernard knows the date.
I understand that Albert knows that it cannot be the 18th or 19th because Bernard would know immediately. Then, with that knowledge I can now eliminate June from the potential months because that would leave only the 17th. And Albert would then be able to deduce the birthdate. I cannot understand the logic behind eliminating the date's in May other than the 19th. Why do you automatically eliminate the entire month of May? If we tried this in real life there would be no way to determine the answer with these words. Neither could know 100% what the date is if you gave 14th, 15th or 16th.
Literally same
The months may and june can be entirely eliminated because albert says "I know Bernard doesn't know." How could he possibly know that? Remember, he knows the month and knows that barnard knows the date. Barnard would immediately know the answer if the date he had was unique (like 19 or 18), but it is not. The only way Albert knows that the date isn't unique is if the month he has doesn't have a unique date. Since both august and june have 1 unique date (19 and 18 respectively), therefore albert doesn't have those months, leading to him realising that barnard wouldn't know the answer as well. Hence, both these months can be eliminated.
Hope this was understandable.
Peace.
You need to think of the puzzle from Albert's and Bernard's point-of-views.
Albert KNEW that the month was July. Thus he also knew that Bernard was given either 14 or 16 and that Bernard could not figure out the month initially.
Bernard KNEW that the number was 16, hence he knew that the month was either May or July. Bernard eliminated May based on what Albert had said.
When Bernard stated that he now knows the month, too, Albert immediately knew that the day cannot be 14.
This puzzle may be hard to comprehend if you only try to think of it from your perspective as an audience. Albert and Bernard had much more information than you; many of the days were excluded because of that.
The dialogue between Albert and Bernard would have been quite different had they been given different month and day, respectively.
I have foolish to look up this video earlier. Sir, I have become your fan
Thanks Bijoy :)
July 16
Can some one explain me ...y he removed may and june months
Please
Bro i think this is wrong
'but I know Bernard doesn't know either' completely eliminates May and June.
Because May and June are the only months with the dates 18 and 19 and these dates appear only once.... If it was these months, B would instantly know
the use of the word "then" in the last step of the puzzle is confusing.
exactly
Last step does not seem to be logical. What if the month given to Albert is aug and date 15th.
Albert's final statement would be, "I still don't know"
Brother pls clarify why u cut may or June,
Rest of the thing is clear....I agreed 18&19 is unique so it has to cut,
But brother why u cut the complete may or June....pls confirm.
Awaiting your response
It's simple dude. If A was told that birth month is May or June, then he couldn't be sure that B also didn't know the answer. Because if birthday was on 19 or 18. B would have got it because 18th and 19th are unique numbers.
Months were not may or June that's why A was sure that B would be confused between non unique dates.
As there are 3 possibilities aug15, jul16, aug17 how did Bernard sure about the birthday
They're all on different days and Bernard knows the day.
Bernard was told that she was born on '16', so if he sees August 15, July 16, and August 17, it is obviously July 16. Albert knew it was July 16 when Bernard said, 'Now I know too' because Albert concluded that Bernard could not have gotten a '14' and said ' I now know her birthday' since there were two '14's July 14 and August '14'. Maybe you are 'NOT remembering' Bernard WAS given the number '16' on the day she was born.
So if you (or anyone else) were to see 344 birthday days (365-11 as only 12 days have '16' as there are 12 months in the year ) and just one has '16' such as September the 16, then September 16 would be her birthday.
We are all assuming (and nothing was said about this in the problem) that (A) must be the first to make a statement!!!
Since nothing was said about this, anyone can make the first statement:
With the silence of (B), (A) knows that he doesn´t have 18 nor 19. And this is the chart (A) sees:
may, 15th and 16th
june, 17th
july, 14th and 16th
august, 14th, 15th and 17th.
(A) would guess the date in his first statement if and only if he had "june", which leads to june, 17th.
Since he says he don´t know, he does not have june, remaining:
may, 15th and 16th
july, 14th and 16th
august, 14th, 15th and 17th.
At this point, (A) CANNOT state that Bernard doesn´t know either, because (B) could have 17, that leads to the unique date august, 17th.
I still think (I comment on this a year ago...) that this problem is poor-formulated. IMHO.
The first sentence generally means it happens first so if A's sentence is written first that means he spoke it first.
"Nothing was said about that" because it's generally accepted that way. It's NOT a "mistake".
Stop looking for mistakes when there's none, it's comparable to disliking.
When (A) stated B doesn't know either, It could mean it's not even August 17..
Then it is 14 or 15 or 16, each of which exist in two months..
When over-smartness ruins the problem to the extent of making it unsolvable!
June 17 is also a ans
His name is Jack not Bernard.He is from green valley.😀
I’m pretty confident August 17th could also be the answer. Let’s break it down:
If Albert knows that Bernard doesn’t know, then we can eliminate June 18th and May 19th. Given that Albert says that he doesn’t know, even with this additional knowledge, then we know it can’t be June 17th either, otherwise he would have known the date. Since Bernard realizes the date immediately after Albert points this out, that means that it was one of the dates eliminated by Albert - the 17th. Since August is the only other month with the 17th, Bernard now knows the date. Since Bernard knows the date, Albert deduces that it’s one of the dates remaining after eliminating June 17th. That leaves August 17th as an answer for both of them to realize under the provided conditions
No, because step #3 in your logic is incorrect:
"Since Bernard realizes the date immediately after Albert points this out, that means that it was one of the dates eliminated by Albert - the 17th."
- Albert eliminated May 15th and May 16th as well, because he actually eliminated the entire months of both May and June right-off-the-bat. So, at this stage now, all of July and August remain as possible candidates. The rest should be straight-forward from there.
1. Albert is sure that Bernard doesn't know the date because the Month he knows does not contain a Day that is UNIQUE (specifically 18 and 19), thus we can eliminate the months May and June. If the Month he was given is either of those, he would have instead said that he knows Bernard MIGHT know the date.
2. Bernard now knows the date because the Day he knows is UNIQUE in the remaining dates. Otherwise, he wouldn't have been sure if he had gotten 14 which appears in both July and August.
3. Albert now knows the date after also eliminating 14 because there is only one date left in the Month he knows. If it had been August, he would have been left with 15 and 17, and he wouldn't have known which yet.
Therefore the answer is July 16.
happy birthday cheryl
Yeh Cheryl se hi puchlo🤯🤯
Hey guys
So basically the answer for the maths problem is July 16 . the reason for it is simple . It is actually because in the dates that were given by Cheryl, only both 18 & 19 appeared once .The rest of he dates appeared twice.that means that Bernard would know the answer if it was 18/19.
Disclaimer !
Sorry peeps the solution is too Long so just search in Google hehhe hdhsbsbs ty
Ps I solved that when I was 7
I got it
Ez
I get why 18 and 19 can be eliminated but how and why do you jump to the conclusion to eliminate all of may and be 100% certain about it, doesnt make sense to me, please explain.
Remember that Albert is not the quizmaster, so he shouldn't know the dates. You need to think from Albert's perspective. Albert only knows what month it is, yet he is confidently asserting that Bernard, who knows the date, doesn't know when the birthday is. How can someone who doesn't know the date but just the month say that Bernard SURELY doesn't know the birthday? It is only possible when the month Albert is told is either July or August in which 18th and 19th dates are not mentioned. Had the month Albert was told been April or June, then Albert cannot say that Bernard doesn't know the birthday, as 18th and 19th are possible dates. I'm reiterating that Albert is just someone who knows the month and not the dates, so unless the month told to him be July or August, he cannot be sure that Bernard doesn't know the exact birthday. Thus, we eliminate May and June.
Difficult tha
August 17 is my answer.
My birthday is on July 16th...
Happy birthday cheryl brother
Questions and answers are not clear
I did it.
singapore maths question.....
June17
Maybe II am missing something here but as A only knows days B only knows months then the solution is impossible as neither has access to the other half of the info. Is this a hoax?
Solve this if u can
Albert:i don't know birthday but I think there there are high chances of Bernard knowing it.
Bernard:first I don't know but now I know.
Albert:but still I don't know
Bernard:hint is independence day of india+(9-3÷1/3+1).
Albert:now I know.
Can u guess the answer
What a bunch of creeps
this is the best other channels just tells the how to do it but does not tells why we u do that you explained me everything properly
These people who think too much outside of the statements given, commenting in the words "If it doesn't happen, then the answer cannot be found". For example, Albert saying "Then I also know when Cheryl's birthday is", and these people ask, "But if he doesn't? Then the answer can't be found", and afterwards outright calling out the logic as "flawed". PLEASE, STOP THOSE STUPID COMMENTS. Yes, the statements have to be really specific, because the statements are SUPPOSED to be specific. That's the idea: the statements MUST be specific enough for an answer to appear from them. Calling out cases where the statements don't happen has NOTHING to do with solving the puzzle, because then we're NOT talking about the puzzle AT ALL. Focus on what is given and don't stray. Please.
Rafael Liman try to prove them that they are wrong instead of crying like a baby. Like Devon Devon’s comment down below, makes lots of sense. If Albert could tell the date, then we could narrow it down to July 16.
First of all, YES, Albert could tell the date IF AND ONLY IF he was told July. Yes, it's TRUE. If he was told August, then the answer cannot be found. Yes, it's TRUE. TRUE. TRUE that he ABSOLUTELY MUST be told July for the puzzle to have an answer. That fact is ALWAYS part of the puzzle. The puzzle had ALWAYS been created with July 16 as the answer. In this puzzle, the possibilities given must be THAT specific, the statements given are actually also specific so that you can find the answer from the possibilities using the statements. This main trick of this puzzle is statements that are seemingly vague, and possibilities that are seemingly picked at random, but they're NOT. This is a PUZZLE. The possibilities are cleverly and deliberately selected. The statements, though seemingly vague, can be used by a clever person to actually narrow down the possibilities. The statements are actually cleverly created so you can get ACTUAL information from it to narrow down the possibilities, while also cleverly disguised as vague and empty statements that don't inform you anything and look like reckless and random nonsense. The statements HAVE information to narrow down the possibilities, but you need to be smart enough to find the information and narrow down the possibilities until only one possibility remain. So, the statements and possibilities given are NOT random. They're NOT. And the answer HAS ALWAYS BEEN chosen. So, Albert could tell the date because the puzzle NEEDS Albert to be able to. The puzzle HAS ALWAYS meant for Albert to be able to tell the date. Pondering about what would happen if the statements, possibilities and answer are different are already thinking OUTSIDE the puzzle. If you're wondering what would happen if the statements, possibilities and answer are different than the puzzle, you ARE NOT talking about the puzzle. Pondering if Albert couldn't tell the date is OUTSIDE the puzzle. Pondering if Cheryl's birthday is NOT on July 16 is OUTSIDE the puzzle.
The logic is NOT "flawed", because you really CAN find the answer with it. Use logic, solve the puzzle, find the answer. NOTHING is wrong. Pondering about different scenarios and outcomes are okay, but it DOESN'T break the logic. There are NO mistakes. In fact, I think the logic used here is brilliant and ingenious.
I throw a dice once. I get an even prime number. What is the number?
Ask me if I get an odd prime number. C'mon.
i dont think the approach is right, you excluded may and june by a reason of 2nd one not know the age now , you should have excluded unique days only not months , you should have excluded 19 and 18 , that is why i think the answer is june 17
Bruh I dont understand
July 16 birthday peoples
How bernard knew cheryl's birthday? He has 3 options(15th, 16th, 17th) to pick. How can he pick 16th?
No, he has just one option because he was given the day (the 16th of month X) :)
He can pick one of the three, because he was already told the correct date.
The logic is flawed. The problem cannot be solved according to the manner in which the initial statement is written. Let's examine the statement, "Cheryl tells Albert and Bernard separately the month and day of her birthday respectively." If you interpret the sentence according to the sentence syntax structure, Cheryl has shared both the month and day with Albert and Bernard. The way the conjunction 'and' is used in this sentence means she did not separately tell one the month and the other the date. Rather she told both Albert and Bernard both the month and date. Also, the placement of the word 'respectively' in this sentence would mean that the order in which Cheryl shared her birthday (both month and day) was first to Albert, and then later to Bernard. To arrive at the logic used to solve the problem, the sentence would have to have been structured differently. Example: Cheryl separately told Albert the month and Bernard the date respectively. In this sentence it is clear that Cheryl told only one part of her birthday information to each of them, and she told Albert before she told Bernard.
Think of it this way, if we don’t have albert’s last statement, we couldn’t tell the exact day since there are 3 answers are true at this point(after Bernard’s statement.) however, If Albert knows the answer, there’s only one exact day that he is possibly knowing the answer.
Yevde hyshar ahe ka te albert ani. Berald je kay naaw ahe tyanche abe yevda chutiya pana koni karat nhi real life madhe jara changle puzzles aana re
but b'day on 15 august is also fulfill the hint
Animation in confusing
I got aug 17
Bro with due respect I think your answer is wrong the possible answer can be August 17, now let us see.
First of all it is easy that May 19 and June 18 cannot be a possible option so just ignore them
Now suppose bernard got the date as 17,now he has the doubt either of it being a June 17 and August 17.
Now access the statement because albert said neither he nor bernard know the answer, so now it is illogical for bernard to think june as a month (because if it is then Albert surely know the date as there is only combination with june), so now bernard come to conclusion that it should be August 17 hence statement 2 is satisfied.
Now access the third statement as soon as bernard said that he knew the answer there is only one possibility of it which is August 17 without breaking the above two statements , all of other possibilities could clearly satisfied the first statement but broke the second statement and hence only option remains is August 17 , plz reply me if something is wrong in this.
I will appreciate it.
June was knocked out in the first statement, or Albert would have said, "Maybe Bernard knows".
If 17, then Albert could not make the final statement because he still doesn't know (could be Aug 15 or 17)
Hi Varshit, your explanation seems to be aligned upto two statements.
Now, albert says the third statement that "Now I also know cheryl's birthday"... that means he has a month which has only one day as the remaining candidate.
If (as per you) albert has August, he could never say that.... because he would be in confusion whether cherly's date of birth is 15th Aug or 17th Aug.
Please let me know if that helps..... I would appreciate even if you don't agree with this reply.... I will try to explain further.
@@LOGICALLYYOURS thanks bro , ur videos are always awesome.
In regarding of this i have to say that if bernard now knows the cheryl birthday it is just because there is only one possibility of it due to which he knows the date that is 17 Aug, if it would Aug 15 then bernard never knows it by just the albert statement so only option remains is 17 Aug so there will be no confusion for albert at last.
@@V7B817 After Albert made the first set of statements..... the minimized set of dates include July 14, July 16, Aug 14, Aug 15, Aug 17.
After Bernard made his statement, it is obvious that July 14 and Aug 14 are out of the game.. because bernard is not having the number 14... else he would not be confident.
Now, the finalists are July 16, Aug 15 and Aug 17......
If (just assume your answer.... ) albert was given the month Aug.... would he be confident now about the date ?? Not at all.... because he would have problem with two days in the month of august...
And please note that....
Albert can say that "He now know the date" if and only if he has an unambiguous month,,,, and out of the three finalists... the only unambiguous month is July...... So Albert was given July.... hence the date must be July 16.
Again... to compare the two cases (July 16 Vs Aug 17).. let's analyze the validity of each set of statements.
Case 1 : Actual birthday is on July 16 :
-Statement Set 1 (by Albert) is valid.
-Statement Set 2 (by Bernard) is valid.
-Statement Set 3 (by Albert) is valid.
Case 2 : Actual birthday is on Aug 17 :
-Statement Set 1 (by Albert) is valid.
-Statement Set 2 (by Bernard) is valid.
-Statement Set 3 (by Albert) is INVALID.
Please analyze the above section carefully.
@@LOGICALLYYOURS Thanks bro for ur reply , i have to say that we r on different paths on this , i understand why you removed the first two months but still doesn't think it is logical, there is some loophole in it, but what i write can't be said that if two statements r valid then third is wrong , all three statements are completely related in my context and if above two are valid then third must have to be a valid.
If we analyse that bernard got day 17 and Albet got month August then by this assumption statement one remains completely valid.
Now bernard has two ambiguous answers and albert has three in the point of their context, now it is important from here, since bernard have two ambiguous answers the one thing in his mind if the answer is June 17 then Albert will clearly know it , if albert got any other month except june he will not know the answer, so bernard had to wait for albert statement as soon as he didn't know the answer means that he got any other month rather than june but it doesn't matter for bernard if not june then it will definitely be August 17 and then bernard confidentally raises his voice.
Now see how the third statement is dependent on above two where the actual debate is , so according to the statement now albert must know the answer without any doubt or possibility of any other answer , so let's see it
We know albert got the month August but there r three possibilities but now the main point , hey wait , but why the bernard becomes so confident after my first statement, what is the reason if i got the August 14 then he will have two possibilities and on the lone basis of my statement he can't come to the conclusion because every month with that date have multiple possibilities so alright it can't be a possibility so what is wrong in aug 15 still exactly the same this date can also not become the reason of surety for bernard , now see the aug 17 this date is only repeated in june 17 and this month have only one option and here oh wait wait wait if i dont know the answer then for this date bernard can conclude the answer and one and only for this date so for albert"hgh i finally know the reason for bernard surety and i also got the answer".
In this i tried my level best to elaborate my perspective my explanation.plz bro assess this and tell me if something is wrong in this.
Fck it was hard
I think they should go with another girl leaving behind this C.😁
It will be a better solution.😜
If Cheryl said to you' One of these three dates are my birthday ; August 15, August 17 and July 16' and then said 'I am going to give you either the month August or July, which month would you want her birthday to be such that you get it right'? of course, in July. That is, if it is in the month of July then you would know for sure her birthday is July 16 as only one date with July . What if her birthday was in August and she gave you August which one of the three dates (August 15 , August 17 or July 16) which month would you ask her to ELIMINATE in order to get her birthday? of course either August 15 or August 17. You certainly would not want her to eliminate July as you then would be left with TWO Augusts and thus would have a 50-50 chance of getting it.
In this puzzle , you eliminate the months of May and June given that there is May 19 and there is June 18 and so Albert WOULD NOT have made the first statement 'I don't know Cheryl's birthday but I know Bernard doesn't know either' ,if he (Albert) has gotten either a May or June' since if Bernard had gotten a 18 or 19 then her birthday would be either June 18 or May 19 . Game won by Bernard, meaning if Bernard had gotten 19 then her birthday would have been May 19 and Albert would have gotten May from Cheryl (remember got July), and if Bernard had gotten 18 then her birthday would have been June 18, and Albert would have gotten June as no other months have the number 18 (only June ) or 19 ( only May).
And this why Albert said 'I don't know Cheryl' birthday but I know Bernard doesn't know either because he (Albert) has gotten July or August. Therefore, Cheryl birthday is either in August or in July.
But when Bernard said ' I didn't know Cheryl's birthday at first but now I know' , he could not have known if he had gotten a '14' since there is a July 14 as well as a August 14 . Therefore, has gotten either 15, 16 or 17. Therefore, Cheryl's birthday is either August 15, August 17 or July 16.
When Albert then said ' Then I now know Cheryl's birthday', we know that
Albert must have gotten "July' for him to say' Then I know Cheryl's birthday' since he COULD NOT HAVE drawn that conclusion if he had gotten 'August' since there is an August 15 and an August the 17 , hence he received 'July' , therefore, her birthday from the following three: August 15, July 16 and August 17 MUST BE July 16, as there is only ONE July. We the audience can only conclude that it is July 16 , after Albert said 'Then I now know her birthday' else without Albert saying that we are stuck at July 16 or August 15 or August 17
so solution : July 16.
Remember , the goal for Albert is to have only ONE July left in order to find Cheryl's birthday while the goal of Bernard is to have just One month left with a '16' in order to find Cheryl's, so though Albert helped by eliminating May and June Bernard when he said 'I don't know Cheryl's birthday but I now Bernard doesn't either' thus leaving only July and August, Albert really helped Bernard by eliminating May 16 since Bernard just want ONE month with 16 , so he wants all the other months with 16 to be eliminated leaving just one. So this how Albert really helped Bernard by eliminating May 16 (since he has eliminated all of dates in May).
And Albert goal just to have One month left , so he doesn't want to have a July 14 and July 16 together, or August 17 and August 15.. So say Cheryl birthday was in August , then Albert would have wanted July 14, July 16, and just one August such as August 15 or 17 but not both because if Albert was to narrow the dates to say July 14, July 16 and August 15, then Cheryl birthday would have been August 15 since there is just one August.
So what Albert and Bernard have in common is they both want just ONE thing left, for Albert just one month either July or August and for Bernard just one month with a '16', so Bernard would want to see May 16 and June 16 together or May 16 and July 16 etc else he would not know her birthday and that's why when Albert statement eliminated May , it is actually the elimination of May 16 that really really helped Bernard, so once Bernard see just one month with a 16 , July 16 he knew that it was that day. What if there was an August 16? then Bernard would not have drawn the conclusion that her birthday was July 16 since would have two months with a 16.
If Bernard had not made any statement , then only Bernard would have known her birthday.
If Albert had gotten August , then Bernard would not have gotten a '16' but either a 17 or a 15 , Yet Bernard still would have known her birthday , but Albert WOULDN'T have known her birthday, but would have known that it was either August 17 or August 15. As said above the answer/solution July 16.
I have see all the videos But the video I like the most is cheryl's birthday riddle
Thanks Rajwinder :) Good choice by the way
A difficult version to this puzzle will be posted soon.
@@LOGICALLYYOURS bro but i still doesn't understand the puzzle , i read all the comments but from none of them i didn't get my answer, i also written my comment with different answer plz read it and reply me , I am awaiting for your answer.
July 16