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Two old men...

by Jin314159
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Jin314159
#1
Jul23-04, 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?
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check
#2
Jul23-04, 09:15 PM
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Ooooh, I like this one.
Got it.
marcus
#3
Jul23-04, 10:58 PM
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Quote Quote by Jin314159
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?
I aint too proud to say the answer

2, 2, 9

marcus
#4
Jul23-04, 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
arildno
#5
Jul24-04, 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..)
The Bob
#6
Jul24-04, 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 ©)
marcus
#7
Jul24-04, 05:18 PM
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Quote Quote by The Bob
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 ©)
The Bob, I already gave the 2,2,9 answer
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 ambiguity----1,6,6 and 2,2,9----and 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
The Bob
#8
Jul25-04, 04:00 AM
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Quote Quote by marcus
The Bob, I already gave the 2,2,9 answer
and I am sticking with that.
I know. I believe I was repeating it. Sorry.

Quote Quote by marcus
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 ambiguity----1,6,6 and 2,2,9----and 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
Point made. I did only spend about 2 minutes in my head doing it. Sorry.

The Bob (2004 ©)
marcus
#9
Jul25-04, 12:46 PM
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Quote Quote by The Bob
...
no problemo The Bob!
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?
Oyéah
#10
Jul25-04, 11:08 PM
P: 21
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.
Chrono
#11
Jul25-04, 11:28 PM
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Quote Quote by Jin314159
What are the ages of the first old man's daughters?
Couldn't you just ask how old the daughters are?
Math Is Hard
#12
Jul26-04, 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?
marcus
#13
Jul26-04, 02:13 AM
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Quote Quote by Math Is Hard
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?
Mathis, there can be some pretty spry old men
Lets change the subject shall we
Jin314159
#14
Jul26-04, 02:27 AM
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Quote Quote by marcus
Mathis, there can be some pretty spry old men
Lets change the subject shall we
lol... yea, males can continue to procreate well into their 70s.
The Bob
#15
Jul26-04, 03:12 AM
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Quote Quote by marcus
no problemo The Bob!
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?
I remember my thread about hats where there are 4 people and they must deduce what colour hat they have on. I don't think I know what you mean really.

The Bob (2004 ©)
Math Is Hard
#16
Jul26-04, 11:01 AM
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Quote Quote by marcus
Mathis, there can be some pretty spry old men
Lets change the subject shall we
hehehehehe... but what about the house address? Just a distraction?
BobG
#17
Jul26-04, 02:20 PM
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Quote Quote by Jin314159
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?
I know these two guys. They live on 1313 Mockingbird Lane. (That actually makes a little more sense if you happen to know the first guy has twin daughters - he's used to looking at doubles of the same thing).

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.
marcus
#18
Jul26-04, 04:16 PM
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Quote Quote by Math Is Hard
hehehehehe... but what about the house address? Just a distraction?
Mathis I think you see that we are just fooling around here and should really change the subject of conversation. But just to respond to your question:

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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