A Math (Logic) Problem Gone Viral
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ernest_t_bass
[h=2]A Math problem that gone viral[/h][INDENT]A question on a quiz for teenage mathletes proved so tricky for Singapore newscaster Kenneth Kong that he posted it to Facebook to find a definitive answer. Now the problem has driven the entire country mad, and it's spreading to the rest of the world.
Here is the question:
Albert and Bernard just met Cheryl. “When’s your birthday?” Albert asked Cheryl.
Cheryl thought a second and said, “I’m not going to tell you, but I’ll give you some clues.” She wrote down a list of 10 dates:
May 15, May 16, May 19
June 17, June 18
July 14, July 16
August 14, August 15, August 17
“My birthday is one of these,” she said.
Then Cheryl whispered in Albert’s ear the month — and only the month — of her birthday. To Bernard, she whispered the day, and only the day.
“Can you figure it out now?” she asked Albert.
Albert: I don’t know when your birthday is, but I know Bernard doesn't know, either.
Bernard: I didn't know originally, but now I do.
Albert: Well, now I know, too!
When is Cheryl’s birthday?
[/INDENT]
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ernest_t_bass
[SP]July16[/SP]
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Heretic
Hmm, so that's where Ohiobucks came up with question #1 for the upcoming sheep season week that I'll be replying to with some variation of "GFY" because shit like this makes my eyes bleed. -
iclfan2
July 16th? Your spoiler click thing doesn't work -
ernest_t_bass
Not sure why. How'd you come up with your answer?iclfan2;1722060 wrote:July 16th? Your spoiler click thing doesn't work -
Laley23
You can eliminate any month with a single date (no same numbers in other months).
Then, you eliminate the similar numbers in the remaining months.
Finally, you know it cannot be the month with multiple dates left. Has to be the month with only 1 date left.
I won't give the answer, but that's how it has to be solved. I don't think there is another possibility... -
iclfan2
I did it like laley. Couldn't be either of top 2 rows bc they have unique dates. Which leaves the bottom 2. They both share 14, so then row 3 only had one other option while 4 had 2 other options.
Sent from my iPhone using Tapatalk -
SportsAndLady
I'll wait for footwedge to chime in before I delve into this. -
iclfan2
The date shows in tapatalk now instead of a spoiler message, unless it's cuz I clicked on it online. Ha too complicated with formatting.
Sent from my iPhone using Tapatalk -
sleeper
I know the answer. -
jmogI have no idea how to do a spoiler hide, so if you don't want to know how to get to July 16th, stop reading...
SPOILER ALERT!!!
The key phrase in the first statement by Albert is that he knows that Bernard doesn't know...
If Bernard had been told 19th or 18th he would know immediately what the birthday is (5/19 or 6/18). Albert only "knows" this because he knows that the month isn't May or June.
So, from the first statement you can eliminate the 5 possible answers in May and June.
When Bernard hears this, he then knows the answer, it narrowed down the months to July and August. Obviously he wouldn't yet know if he had been told the 14th as both July and August have the 14th. So his statement leaves only 3 dats, 7/16, 8/15, and 8/17.
Albert then saying he knows finalizes the solution. If it was August Albert still couldn't 'know' as there would be two dates left in August. So it has to be July 16. -
ernest_t_bass
WTF does that have to do with anything?jmog;1722081 wrote:(which just so happens to be my oldest son's birthday). -
1_beast
Not july 16. Im going with may 19 -
gutThis was hard for people?
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friendfromlowryAlbert and Bernard just met Cheryl. “When’s your birthday?” Albert asked Cheryl.
Cheryl thought a second and said, “I’m not going to tell you, but I’ll give you some clues.” She wrote down a list of 10 dates:
Would have walked away at this point if I were Albert or Bernard -
ohiobucks1
Goddamnit, you fools ruined my Sheep joke/question lol -
gerb131
2. The answer is 2. -
Glory Days
How hot is Cheryl? -
WebFire
So Benard knows it's 5/19 or 6/18, but Albert knows it's not May or June.jmog;1722081 wrote: If Bernard had been told 19th or 18th he would know immediately what the birthday is (5/19 or 6/18). Albert only "knows" this because he knows that the month isn't May or June.
What the fuck did I just read? -
sleeper
I think that's a bit unfair. I had to at least write the logic down on paper to figure it out and I'm probably the person with the highest IQ here(besides Con_Alma of course).gut;1722135 wrote:This was hard for people?
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ZWICK 4 PREZ
jmog;1722081 wrote:I have no idea how to do a spoiler hide, so if you don't want to know how to get to July 16th, stop reading...
SPOILER ALERT!!!
The key phrase in the first statement by Albert is that he knows that Bernard doesn't know...
If Bernard had been told 19th or 18th he would know immediately what the birthday is (5/19 or 6/18). Albert only "knows" this because he knows that the month isn't May or June.
So, from the first statement you can eliminate the 5 possible answers in May and June.
When Bernard hears this, he then knows the answer, it narrowed down the months to July and August. Obviously he wouldn't yet know if he had been told the 14th as both July and August have the 14th. So his statement leaves only 3 dats, 7/16, 8/15, and 8/17.
Albert then saying he knows finalizes the solution. If it was August Albert still couldn't 'know' as there would be two dates left in August. So it has to be July 16.1_beast;1722125 wrote:Not july 16. Im going with may 19
jmog literally just explained it for you lol -
Laley23
Took me a good amount of time as well.sleeper;1722259 wrote:I think that's a bit unfair. I had to at least write the logic down on paper to figure it out and I'm probably the person with the highest IQ here(besides Con_Alma of course). -
WebFire
Not to mention that there isn't anybody that would be able to figure this out by only having the conversation above with someone.Laley23;1722281 wrote:Took me a good amount of time as well. -
Laley23
??? I think we are to assume that the 2 hold a conversation about what they are told.WebFire;1722283 wrote:Not to mention that there isn't anybody that would be able to figure this out by only having the conversation above with someone. -
WebFire
Point is, if this conversation was held in real life as it is above, no one would know the answer.Laley23;1722285 wrote:??? I think we are to assume that the 2 hold a conversation about what they are told.