Ages Of Children

Two mathematicians meet on the street and one says to the other, "I bet you can't guess the ages of my 3 children" (all integer ages).The 2nd mathematician says, "I'll take your bet but only if you give me enough information to solve it."

The 1st agrees, and says, "The product of my 3 children's age is 36."
"That is not enough information."

"Right you are!" he looks around, spies an address on a building and says, "The sum of my children's age is the same as the address over there.".

Thinking a little bit; "That still isn't enough information.""Right you are again!  My eldest son has red hair."

After some thinking the 2nd mathematician won the bet.