On 21 Feb 2007, Mike McCarty wrote: > Chris Bannister wrote: > >Or the 12 billiard balls where one is lighter/heavier and all you have > >is a set of balance scales. > > > >You have to find which one it is plus whether its lighter or heavier in > >3 weighings. > > > >I think/hope its 3 :-) > > I see how to do it in 4. In fact, I found two ways. I haven't > found a way in 3 (yet). > > How about, you have N bags of coins. Each bag has some number > of coins in it, each one has at least N coins. You know that > one of the bags has counterfeit coins in it, and you know that > the counterfeit coins each weigh one gram less than real coins. > You have a scale. How, in one weighing, can you find which > bag has the counterfeit coins? > > Mike
Hint: think about swapping some of the coins around. -- Anthony Campbell - [EMAIL PROTECTED] Microsoft-free zone - Using Linux Gnu-Debian http://www.acampbell.org.uk (blog, book reviews, on-line books and sceptical articles) -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
