A. Answers to Exercises
Every exercise is answered here (at least briefly), and some of these answers go beyond what was asked. Readers will learn best if they make a serious attempt to find their own answers BEFORE PEEKING at this appendix.
The authors will be interested to learn of any solutions (or partial solutions) to the research problems, or of any simpler (or more correct) ways to solve the non-research ones.
(The first finder of every error in this book will receive a reward of $2.56.)
1.1 The proof is fine except when n = 2. If all sets of two horses have horses of the same color, the statement is true for any number of horses.
Does that mean I have to find every error?
1.2 If Xn is the number of moves, we have X0 = 0 and Xn = Xn–