McDonald's sells Chicken McNuggets in packages of 6, of 9, and of 20.  So
it is possible to buy 6 Chicken McNuggets or 29 Chicken McNuggets, but it
is not possible to buy 5 or 7.

What is the largest number (less than 1000) of Chicken McNuggets which it
is impossible to buy?


There will be a $1 prize for the best correct solution submitted by a
midshipman.

A solution is "correct" if it answers the question correctly and explains
the answer; a solution is "best" if it includes the clearest correct
explanation.  Solutions are due by noon on Thursday, November 5, 1998.
Submit solutions to Prof. Hanna at mathprob@nadn.navy.mil, or via the
mailbox in Chauvenet 301.


--------------------------

Correct solutions to problem #78, the square in the triangle, came from
Midn. 1/c Bunchongchuitr (who wins the $1 and whose solution is posted on
Chauvenet lab-deck bulletin board) and Midn. 3/c Mikolay.  Midn. 2/c
Yeager also sent in the correct answer, but without an explanation.