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Two old men...by Jin314159
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#1
Jul2304, 08:55 PM

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Two old men were talking on the porch.
The first old man says: "I have three daughters. The sum of their ages is equal to the same number as this house's address (we don't know the number, but these two old men do). The product of their ages is 36." The second old man thought for a moment and says: "That's not enough information." The first old man says: "My oldest daughter has green eyes." Then second old man figured out the ages of the first old man's daughters. What are the ages of the first old man's daughters? 


#3
Jul2304, 10:58 PM

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2, 2, 9 


#4
Jul2304, 11:01 PM

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Two old men...
the ambiguity (which forced him to say a sentence indicating that
the oldest was one person and not twins) is the possibility of 1,6,6 but it cant be that because the oldest has green eyes so it has to be 2,2,9 


#5
Jul2404, 07:19 AM

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Unacceptable, unless we are talking about siamese twins
If one of the twins are born prior to the other, we certainly may say that that twin is the oldest EDIT: (D**n, I forgot about caesarian(?) birth..) 


#6
Jul2404, 03:31 PM

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It is either 2, 3 and 6 or 2, 2 and 9.
As the oldest daughter has green eyes you can assume that the oldest and next oldest are not twins, otherwise it would have been oldest daughters. The Bob (2004 ©) 


#7
Jul2404, 05:18 PM

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and I am sticking with that. I do not think that what you suggest (2,3,6) is a possible answer I think that because the second man said "that's not enough information" the point is that if the housenumber had been 11 then he would not have asked for more information because there is no ambiguity: there's only one possible answer (2,3,6 is the only set of positive integers that work) so we know that the housenumber was NOT 11 the only thing left is for it to be 13 because this has ambiguity1,6,6 and 2,2,9and makes a reason for him to say "that's not enough information" at that point he is told that one single daughter is the oldest and he knows it is 2,2,9 


#8
Jul2504, 04:00 AM

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The Bob (2004 ©) 


#9
Jul2504, 12:46 PM

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BTW I cannot reconstruct from memory a wellknown puzzler about the 3 people and the smudge on the forehead or someone is wearing a funny hat and they are supposed to deduce who. Maybe I always avoided getting acquainted with this problem because I found it taunting. Can you remember or reconstruct it? 


#10
Jul2504, 11:08 PM

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People who have twins or triplets still consider the first born, the oldest, even if they are all the same age. Could they be 12 year old triplets? 3x12? The sum of the age would be the same as the product.



#11
Jul2504, 11:28 PM

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#12
Jul2604, 01:05 AM

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I don't understand why there are two OLD men talking when the daughters are so young. Is this just to throw you off track? And what does the address of the house have to do with it?



#13
Jul2604, 02:13 AM

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Lets change the subject shall we 


#14
Jul2604, 02:27 AM

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#15
Jul2604, 03:12 AM

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The Bob (2004 ©) 


#16
Jul2604, 11:01 AM

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#17
Jul2604, 02:20 PM

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Both of these guys are old, but the second is old to the point of senility, which is why he's having trouble remembering the ages of his own granddaughters. 


#18
Jul2604, 04:16 PM

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no Mathis, the house address is an essential part of the problem It could have been rephrased by saying that First whispers to the other what the sum of the ages is. the important thing is they both know the sum (even tho we do not) The information we start with is A. the ages are whole numbers (assumed) B. the ages multiply to make 36 C. Even though Second O.M. knows the sum, he still cannot deduce the ages and has to ask for more info. from this one can deduce that the sum is NOT 11 because if it were then he would be able to say 2,3,6 THERE ARE NO OTHER 3 NUMBERS THAT ADD UP TO 11 and multiply to 36. Also we can deduce the sum is not 10 (he didnt whisper "ten" to his friend) because then the ages would have to be 3,3,4. Also we can deduce that he didnt whisper "38" because then the unique possible answer would be 1,1,36 So, mathis, it is as if we can eavesdrop on what he whispers We also know he didnt whisper "21" for the sum because then the immediate inference is 1,2,18 And he didnt whisper "16" because then Second O.M. would deduce 1,3,12 So the only thing he can have whispered was "13" because for sum of 13 there are two possibilities 2,2,9 and 1,6,6. So that is why Second OM said "tell me more information" You can check that 13 is the only possible whole number besides what we already excluded. :surprise: 


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