Problem pp. 57-58 is misanalysed. Is the implication of the title that this book is for the average player? Of course, even the world champion might be improving. So far these problems are really quite challenging and the fact of the misanalysis in itself reflects the complexity of the problems. Further, I'm not sure if, in order to keep the analysis short, there has been a temptation to simplify the nature of the problems.
The problems are interesting, but tougher than you might expect.