Ann and Bob have the following conversation:

Ann: How old are your three kids, again?

Bob: The product of their ages is 36.

Ann: I can't figure it out from that information.

Bob: The sum of their ages is the same as your house number.

Ann: That's still not enough information.

Bob: The one who's older than the others has red hair.

Ann: Thanks! Now I've got it.

How old are Bob's kids?

Source: Tony Zhou (via Richard Neal)