wu :: forums (http://www.ocf.berkeley.edu/~wwu/cgi-bin/yabb/YaBB.cgi)
riddles >> hard >> Infinite Quarter Sequence (Solution)
(Message started by: kenny on Jul 30th, 2002, 12:40pm)

Title: Infinite Quarter Sequence (Solution)
Post by kenny on Jul 30th, 2002, 12:40pm
I sorta figured this out by accident, but here's the solution.

First, all the coins are in pile A.  Move 20 coins to pile B.

If there are now N tails in pile A, there must be (20 - N) tails in pile B, and thus N heads in pile B.

Flip all coins in pile B.  There must now be N tails in pile B.

Done.

-- Ken

Title: Re: Infinite Quarter Sequence (Solution)
Post by Marshall on Aug 9th, 2002, 11:43am
I like it; nice job.



Powered by YaBB 1 Gold - SP 1.4!
Forum software copyright © 2000-2004 Yet another Bulletin Board