The Mathematician's daughters

[John Larkin]

Well, that link helped alot Chris, thanks! Now here's a question: Is it farther to Memphis, or by bus?

 

[lyonsd]

I'll explain it on Monday.

 

[lyonsd]

SOLUTION

Two mathematicians meet in the street and start to talk.

"I heard you already have three children now."

"Yes, that's right, I have three daughters."

"How old are they?"

"Well, if you add up their years, you get 13

All the combinations of three positive numbers (excluding 0) that can be added to get 13...

comb. sum prod
1, 1,11 13 11
1, 2,10 13 20
1, 3, 9 13 27
1, 4, 8 13 32
1, 5, 7 13 35
1, 6, 6 13 36
2, 2, 9 13 36
2, 3, 8 13 48
2, 4, 7 13 56
2, 5, 6 13 60
3, 3, 7 13 63
3, 4, 6 13 72
3, 5, 5 13 75
4, 4, 5 13 80

and if you multiply their years then you get the same number as the house number over there."

"Really! But that's yet not enough for me."

Why isn't it enough information for him? Because the house number he was looking at was "36". How do we know that? Because if it were any other number, it would have been enough info for him to know the daughters' ages, since every other product appears only once.

So we know the girls' ages must be either

1, 6 and 6, or

2, 2 and 9

"That's right, I have to add that my eldest daughter has a dog."

He has an "eldest daughter". That means it must be "2, 2 and 9" because if it were "1, 6 and 6", then he wouldn't have an "eldest daughter", he'd have TWO eldest daughters.

"I see, now everything is clear to me."

 

[1987 GN]

That is pretty interesting. Do you know of a website to get more puzzles/riddles like that?

 

[2FAST4U]

Yeah, if you have any links to riddle sites, please don't EVER send them to me. This one gave me a headache.

 

[blackbird]

GAY GAY GAY!!!





just kidding

 

[Quick6'n'-K.C.]

OH YEAH, so how old was the DOG???????????????