It was always understood that 'research-level' includes (advanced) graduate material. Thus, the level of the question is not in itself a problem.
However, questions that are mere reproductions of problems from assignments or books, or even just are presented like those, often are not well-received.
Thus, I'd say you likely could ask questions concerning the problems in the book, while just posting the problems in the book verbatim likely will cause problems.
Your post on math.SE is somewhat in the middle. It is not a pure reproduction, but there is also not much done in addition either.
It is hard to predict what would happen if you had posted that here.