Aust MS Gazette - Puzzle Corner 18

The Australian Mathematical Society Gazette’s Puzzle Corner is a bimonthly column
containing a handful of entertaining mathematical puzzles.  The puzzles cover a range of
difficulties, come from a variety of topics, and require a minimum of mathematical
prerequisites to be solved.  

You can find the Puzzle Corner, as well as the rest of the Gazette online at:
http://www.austms.org.au/Gazette+Volume+37+Number+3+July+2010

Please check it out when you feel like trying out random fun problems! Should you happen
to solve any, be sure to send your solution to us.  In each Puzzle Corner, the reader
with the best submission will receive a book voucher to the value of $50, not to mention
fame, glory and unlimited bragging rights! Entries are judged on the following criteria,
in decreasing order of importance: accuracy, elegance, difficulty, and the number of
correct solutions submitted.  

Please e-mail solutions to ivanguo1986@gmail.com or send paper entries to: Kevin White
School of Mathematics and Statistics University of South Australia Mawson Lakes SA 5095 

The deadline for submission of solutions for Puzzle Corner 18 is 1 September 2010.  The
solutions to Puzzle Corner 18 will appear in Puzzle Corner 20 in the November 2010
issue of the Gazette.  Thank you! 

Ivan