Hello: the number of students in the master's examination depends on the specific regulations of the school you apply for. Every school has different rules. Generally speaking, it is a bit difficult to count to three. The difference between Math 1, Math 2, Math 3 and Math 4 lies in the requirement of knowledge: Math 1 has the widest knowledge and is not difficult, Math 3 is the second, Math 4 is slightly lower, Math 2 has a narrow knowledge and few questions, but the questions are difficult. In short, each has its own advantages and disadvantages, and it is not easy on the whole!