The solution to each problem is given, and often times, more than one solution is given. The solutions presented are generally concise and elegant (and correct, of course) - in other words, they are mathematically well written.
The book also gives the results - the names of the top five individuals and the top five teams for each year. Also given with each solution is the number of contestants among the top 250 or so who scored 10 points (a perfect score), 9 points, 8 points, ... 1 point - this is useful in estimating the degree of difficulty of the problem.
I didn't find any typos, errors, etc. The editors have done a good job with the book.
The elegant simplicity of the solutions presented to the seemingly complex problems that face the characters is a biting comment on our own society's predilection for grinding out the answer to everything, when in reality what we need when confronting humanity's great issues is a sense of perspective.
However, I found the characters somewhat flat. Why, for example, does the set N choose to define himself in such narrow terms? Has he no dreams, no fantasies, no weaknesses, nothing but a recursive definition? Many of the characters had similar problems; I had difficulty relating to the motives behind some of their self-simplifying actions.
Overall, though, this is a brilliant social commentary and a heartrending story. It is truly a new American classic in the tradition of Pynchon, Vonnegut, and Faulkner.