Hard brain teasers for school two old friends, jack and bill, meet after a long time. three kids jack: hey, how are you, man? bill: not bad, got married and i have three kids now. jack: that's awesome. how old are they? bill: the product of their ages is 72 and the sum of their ages is the same as your birth date. jack: cool..but i still don't know. bill: my eldest kid just started taking piano lessons. jack: oh, now i get it. how old are bill's kids?