Followup to: <01bcf44e$fef00320$8de52ac2@jon> By author: "Jonathan Pearce" <email@example.com> In newsgroup: sci.math > > Does anybody know of an elegant solution to the twelve billiard ball > problem? > > (Twelve apparently identical billiard balls, one of which is slightly > heavier than the rest, determine which is the heavier one making only three > weighings.) > > I would be very grateful for a reply. > > JVP.
Why make it so easy? Twelve billiard balls (gold bars, whatever...); exactly one is *either* lighter *or* heavier than the others; find which one it is *and* if it is lighter or heavier, in three weighings by a balance scale.
My music teacher gave me this problem back in sixth grade. It's solvable (and yes, I found the solution.)