p. 20, problem 13: should be "2" (not "1) if |i-j|=1 (thank you Anthony A.)
p. 23, problem 22: should be "diameter" instead of "radius"; clarification: the new coin mush be of the same size as the previous ones (discovered by the author)
p. 86, 5(d): should be "implication" instead of "biconditional" (thanks Anthony A.)
p. 109, 15: need to indicate that this solution is to part (a) (discovered by the author)
p. 133: need solution to problem 5 (discovered by the author)