Riddles!

[.Memories.]

(05-13-2013 06:28 AM)awpertunity Wrote:  Haha yeah but since he's a math guy I want to stump him with a math one! How about this...

Two men are paying their tab at a bar and talking about their kids. One man says to the other that he has 3 kids, and the product of their ages is 36 and that the sum of their ages is equal to the cost of their bar tab. The other man says, "Okay.... but I can't figure out how old your kids are from that". The first man agrees and adds, "The oldest one is a boy!" to which the second man replies, "Ah, okay I got it now!"

How old are the three kids?

The first piece of crucial information is the fact that the man says he can't figure it out from what the other man told him. That means that the sum of the three ages has to appear at least twice out of the factors of 36. For example, it can't be 9 * 4 * 1 (= 36) because no other three factors of 36 sum to 14 (= 9 + 4 + 1). If this were the case, he would not need more information from the guy. Therefore, it must be either 9 + 2 + 2 = 13 or 6 + 6 +1 = 13 because they both sum to 13 (and are the only non-unique sums).

The next bit of info, that there is an oldest, finishes it off. There cannot be an "oldest" if there are twins of age 6. Thus, we know the kids' ages are 9, 2, and 2.