MATH: How can you figure this out?

[gorcorps]

The answer should be June 17.

The thing that is stupid with this problem is it's not a normal flow of conversation. It projects an image that these lines are being said one after the other, when in reality the flow is more like:


Cheryl then tells Albert & Bernard the month & day

<Albert and Bernard separately study all the possibilities for a few minutes>
Albert: I don't know her b-day, but I can deduce Bernard does not know
<Albert and Bernard study all the possibilities for a few more minutes>
Bernard: At first I didn't know but now I know
<Albert studis all the possibilities for a few more minutes>
Albert: I know now


If worded like that it leads people towards the proper answer.

dumb dumb head

 

[Carson Dyle]

The answer should be June 17.

The thing that is stupid with this problem is it's not a normal flow of conversation. It projects an image that these lines are being said one after the other, when in reality the flow is more like:

Cheryl then tells Albert & Bernard the month & day

<Albert and Bernard separately study all the possibilities for a few minutes>
Albert: I don't know her b-day, but I can deduce Bernard does not know
<Albert and Bernard study all the possibilities for a few more minutes>
Bernard: At first I didn't know but now I know
<Albert studis all the possibilities for a few more minutes>
Albert: I know now

If worded like that it leads people towards the proper answer.

Logically, your wording is exactly the same. But you still got the wrong answer. Explain how you get June 17??

 

[BergeLSU]

This is just another version of this very old logic puzzle:

Cannibals ambush a safari in the jungle and capture three men. The cannibals give the men a single chance to escape uneaten.

The captives are lined up in order of height, and are tied to stakes. The man in the rear can see the backs of his two friends, the man in the middle can see the back of the man in front, and the man in front cannot see anyone. The cannibals show the men five hats. Three of the hats are black and two of the hats are white.

Blindfolds are then placed over each man's eyes and a hat is placed on each man's head. The two hats left over are hidden. The blindfolds are then removed and it is said to the men that if one of them can guess what color hat he is wearing they can all leave unharmed.

The man in the rear who can see both of his friends' hats but not his own says, "I don't know". The middle man who can see the hat of the man in front, but not his own says, "I don't know". The front man who cannot see ANYBODY'S hat says "I know!"

How did he know the color of his hat and what color was it?

 

[irishScott]

This is one of those things that's really easy to work out on paper but horribly worded; so it's easy to misinterpret the conditions.

 

[mrjminer]

This has to be the most poorly worded question I've ever seen. With the poor wording, there is no way to answer the question (unless we assume the statements they make apply to the shitty wording of the preceding part of the question to identify what each were actually told).

Taking a leap away from the shitty grammar of the "Cheryl then tells Albert ... respectively", assuming it meant:

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

Albert's first statement:
-You know it can't be the 18th or 19th since there is a possibility Bernard would have known the birthday if it was one of these days (only one month with 18 and one with 19). This eliminates May and June.

At this point, you now know:
+Could be July, or August.
+Could be 14th, 15th, 16th, or 17th.

Bernard's first statement:
-He now knows May and June have been eliminated, and now knows the birthday. This means that whatever day he got must be present in either May or June. Now that he is certain he knows the birthday, it also means that one of the day he got must only be present in either July or August, which eliminates the 14th.

At this point, you now know:
+Could be July, or August.
+Could be 15th, 16th, or 17th.

Albert's second statement:
-He now knows that the 14th has been eliminated, which means that the only way he can know her birthday is if the month is July, otherwise he would still not be able to discern between August 15th and 17th.

The answer is July 16th. Yea, it's a bitch. Took some time to figure out

 

[dank69]

This is just another version of this very old logic puzzle:

Spoiler

If person in rear sees two white hats he would know his hat is black. Since he says he doesn't know, front and middle must either both have black hats or one black and one white. Knowing this, if person in middle sees white he knows his must be black. Since he doesn't know, person in front now knows that person in middle must see black.

 

[Slew Foot]

This has to be the most poorly worded question I've ever seen. With the poor wording, there is no way to answer the question (unless we assume the statements they make apply to the shitty wording of the preceding part of the question to identify what each were actually told).

Taking a leap away from the shitty grammar of the "Cheryl then tells Albert ... respectively", assuming it meant:

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

Albert's first statement:
-You know it can't be the 18th or 19th since there is a possibility Bernard would have known the birthday if it was one of these days (only one month with 18 and one with 19). This eliminates May and June.

At this point, you now know:
+Could be July, or August.
+Could be 14th, 15th, 16th, or 17th.

Bernard's first statement:
-He now knows May and June have been eliminated, and now knows the birthday. This means that whatever day he got must be present in either May or June. Now that he is certain he knows the birthday, it also means that one of the day he got must only be present in either July or August, which eliminates the 14th.

At this point, you now know:
+Could be July, or August.
+Could be 15th, 16th, or 17th.

Albert's second statement:
-He now knows that the 14th has been eliminated, which means that the only way he can know her birthday is if the month is July, otherwise he would still not be able to discern between August 15th and 17th.

The answer is July 16th. Yea, it's a bitch. Took some time to figure out

Bernards first statement implies that he already knows the month and date

 

[Printer Bandit]

what kind of sadist comes up with problems like this?

 

[GasX]

The answer should be June 17.

The thing that is stupid with this problem is it's not a normal flow of conversation. It projects an image that these lines are being said one after the other, when in reality the flow is more like:


Cheryl then tells Albert & Bernard the month & day

<Albert and Bernard separately study all the possibilities for a few minutes>
Albert: I don't know her b-day, but I can deduce Bernard does not know
<Albert and Bernard study all the possibilities for a few more minutes>
Bernard: At first I didn't know but now I know
<Albert studis all the possibilities for a few more minutes>
Albert: I know now


If worded like that it leads people towards the proper answer.

you have no imagination...

 

[mrjminer]

Bernards first statement implies that he already knows the month and date

Right, he didn't know it, but he knows it now. Bernard already knows it is July 16th at that point since he knows the day is 16. We still cannot determine the birthday at that point, though. From our perspective, the 15th, 16th, or 17th are all valid days -- until we get Albert's second statement. Then we know that since Albert knows, the month must be July, and the only valid day in July is the 16th.

 

[DrPizza]

The answer should be June 17.

The thing that is stupid with this problem is it's not a normal flow of conversation. It projects an image that these lines are being said one after the other, when in reality the flow is more like:


Cheryl then tells Albert & Bernard the month & day

<Albert and Bernard separately study all the possibilities for a few minutes>
Albert: I don't know her b-day, but I can deduce Bernard does not know
<Albert and Bernard study all the possibilities for a few more minutes>
Bernard: At first I didn't know but now I know
<Albert studis all the possibilities for a few more minutes>
Albert: I know now


If worded like that it leads people towards the proper answer.

If the problem, as presented, happened to you, you'd need a few minutes to go from one statement to the next? Seriously?

 

[DrPizza]

This is just another version of this very old logic puzzle:

I think one of my favorites in this genre is "100 prisoners, to be executed the next day. But, the King decides to give them a chance. The next morning, the prisoners are to be lined up in a row. Each will have either a red or black hat randomly chosen to be placed on their head. They will not be able to see what's placed on their own head, or on the head of those behind them, but will be able to see all of the hats as they're being placed on the men in front of them. If a prisoner correctly identifies the color of hat on his head, he is allowed to live. If any prisoner says anything other than "red" or "black", every one of them is shot on the spot. If any prisoner cheats in any way, they're all shot on the spot. The prisoners know what is to happen, and the night before, plot to determine a way to ensure that a maximum number of them possible will survive.

What is the maximum number that can be guaranteed to survive, if the prisoners correctly follow an agreed upon procedure.

I'll refrain from giving the answer for a day or two. It's more than most people would suspect. A lot more.

 

[Carson Dyle]

If the problem, as presented, happened to you, you'd need a few minutes to go from one statement to the next? Seriously?

Really. I find that even more frightening than someone being unable to solve the relatively simple logic problem. The problem was obviously written by a non-native speaker (turns out it's from Singapore), but it's not THAT poorly written that you can't easily figure out exactly what is being said.

 

[irishScott]

Really. I find that even more frightening than someone being unable to solve the relatively simple logic problem. The problem was obviously written by a non-native speaker (turns out it's from Singapore), but it's not THAT poorly written that you can't easily figure out exactly what is being said.

Actually it is. They don't specify a setting for Albert and Bernard. It took me a few minutes to figure out they were just speaking in the same room, to the air I guess. I assumed they were having a conversation or separate interview or something, and that Albert had just told Bernard the month, as inferred by "I know now." (and I was thinking "duh, then why wouldn't Bernard know the answer at that point?").

Call me a fool if you like, but people frame problems differently. That problem gave me people with no social context, so my mind naturally supplied one that bungled my ability to solve the problem quickly. Clunky phrasing didn't help either. Honestly shitty word problems like this are part of why I hated primary and high school. The logic is almost always straightforward, but the conditions are almost always stated in an imprecise, inconsistent, incomplete, and sometimes downright contradictory manner.

 

[irishScott]

If the problem, as presented, happened to you, you'd need a few minutes to go from one statement to the next? Seriously?

In real life there would be observable context that would eliminate the confusion, and the option of asking questions. Said context was not supplied by the problem as written, and was up to the reader to "fill in".

 

[gorcorps]

Actually it is. They don't specify a setting for Albert and Bernard. It took me a few minutes to figure out they were just speaking in the same room, to the air I guess. I assumed they were having a conversation or separate interview or something, and that Albert had just told Bernard the month, as inferred by "I know now." (and I was thinking "duh, then why wouldn't Bernard know the answer at that point?").

Call me a fool if you like, but people frame problems differently. That problem gave me people with no social context, so my mind naturally supplied one that bungled my ability to solve the problem quickly. Clunky phrasing didn't help either. Honestly shitty word problems like this are part of why I hated primary and high school. The logic is almost always straightforward, but the conditions are almost always stated in an imprecise, inconsistent, incomplete, and sometimes downright contradictory manner.

I'd be there with you if nobody was able to figure it out with the wording presented, but people are figuring it out as written. Don't blame the question if other people are getting it right.

Reminds me of :

 

[radhak]

Honestly Cherly is a little bitch for not just saying what her birthday is. Also Albert and Bernard should just tell each other what Cheryl said instead of beating around the bush about it.

:thumbsup:

 

[disappoint]

I'd be there with you if nobody was able to figure it out with the wording presented, but people are figuring it out as written. Don't blame the question if other people are getting it right.

Yeah? Maybe they just googled it, and Irishscott tried to actually solve it with no help at all.

 

[disappoint]

So is anyone able to do this in their head without scrap paper? I think writing stuff down so you don't lose track of what each of those beta fucks are thinking at each step allowing this broad to fuck with their heads makes it easier.

 

[dank69]

So is anyone able to do this in their head without scrap paper? I think writing stuff down so you don't lose track of what each of those beta fucks are thinking at each step allowing this broad to fuck with their heads makes it easier.

I did both problems in my head without Google.

 

[dank69]

I think one of my favorites in this genre is "100 prisoners, to be executed the next day. But, the King decides to give them a chance. The next morning, the prisoners are to be lined up in a row. Each will have either a red or black hat randomly chosen to be placed on their head. They will not be able to see what's placed on their own head, or on the head of those behind them, but will be able to see all of the hats as they're being placed on the men in front of them. If a prisoner correctly identifies the color of hat on his head, he is allowed to live. If any prisoner says anything other than "red" or "black", every one of them is shot on the spot. If any prisoner cheats in any way, they're all shot on the spot. The prisoners know what is to happen, and the night before, plot to determine a way to ensure that a maximum number of them possible will survive.

What is the maximum number that can be guaranteed to survive, if the prisoners correctly follow an agreed upon procedure.

I'll refrain from giving the answer for a day or two. It's more than most people would suspect. A lot more.

Procedure is for each person to say red or black normally if that is the true color of the hat in front of them, and say red or black in an abnormal accent if it is not the color of the hat in front of them. Start with person in the back who has a 50-50 shot of his hat matching the one in front of him. The other 99 live. I am certain this isn't the answer you are looking for. Instead of normal/accent they could also do whisper/normal or whisper/yell or normal/yell.

 

[Meghan54]

99

 

[disappoint]

I think one of my favorites in this genre is "100 prisoners, to be executed the next day. But, the King decides to give them a chance. The next morning, the prisoners are to be lined up in a row. Each will have either a red or black hat randomly chosen to be placed on their head. They will not be able to see what's placed on their own head, or on the head of those behind them, but will be able to see all of the hats as they're being placed on the men in front of them. If a prisoner correctly identifies the color of hat on his head, he is allowed to live. If any prisoner says anything other than "red" or "black", every one of them is shot on the spot. If any prisoner cheats in any way, they're all shot on the spot. The prisoners know what is to happen, and the night before, plot to determine a way to ensure that a maximum number of them possible will survive.

What is the maximum number that can be guaranteed to survive, if the prisoners correctly follow an agreed upon procedure.

I'll refrain from giving the answer for a day or two. It's more than most people would suspect. A lot more.

None survive because it's very likely among 100 prisoners that at least one of them will be suicidal and homicidal and will get everyone killed by uttering just one word.

 

[Sonikku]

The answer is Cheryl's a bitch and I'm not going to her damn party.

 

[darkewaffle]

Yeah, the 'tense' threw me off. As I read it I didn't take Albert's initial statement to mean that Bernard 'could not' know, just that he does not know - but I suppose that is redundant.

Either way I didn't quite make the connection between Albert's statement and removing May/June, I thought it was a premise, not something that he had actually determined.