Although I have never used it, the answer sheet has been detached. There are faint marks on the back of the answer sheet (such as advanced problems) where I put an "X" in pencil and erased it. (It was a symbol meaning "you don't have to do the advanced problems," but I ended up not doing them at all...) The problem book itself is completely untouched and unused. For those who understand the above. #JuniorHighSchoolEntranceExam #AdvancedLearning #ProblemBook #Textbook