1. compound problem: compound problem is a problem that combines multiple concepts or skills, and requires candidates to comprehensively use a variety of mathematical knowledge and problem-solving methods to analyze and solve problems. This kind of problem usually requires patience and flexibility to find the right solution.
2. permutation, combination and probability: permutation, combination and probability questions usually require candidates to have strong combinatorial analysis ability and flexible use of mathematical thinking ability, involving complex counting skills and probability models. This kind of topic is more difficult for candidates who are not familiar with relevant knowledge points.
3. Advanced Algebra: The topic of advanced algebra involves abstract algebraic concepts such as linear space, linear equations and matrix theory. To examine the examinee's ability to understand and apply abstract mathematical concepts. This kind of topic may be difficult for candidates who have not been exposed to relevant knowledge.
4. Mathematical analysis: The topics of mathematical analysis involve concepts and theories such as limit, continuity, differential and integral. This kind of topic may be easier for candidates with strong logical thinking ability and in-depth understanding of mathematical analysis, but more difficult for candidates with weak mathematical foundation.
It should be noted that the definition of a problem varies from person to person, and the difficulty of different people may also be different. For some people who have learned relevant knowledge and have some experience in solving problems, they may find other problems more difficult. Therefore, in the process of preparing for the exam, it is suggested to review and practice according to your actual situation and your own advantages and disadvantages.