It won't be difficult, because economics is the simplest high number for postgraduate entrance examination. Only need math three, including calculus, linear algebra and probability theory. Math 1 is the most difficult for people majoring in mathematical physics, and Math 2 is relatively simple. Math III is the simplest marketing major. It seems that some majors don't need to take the math test, such as some management majors, but it will take some time if you want to take the postgraduate entrance examination. After all, advanced mathematics is not very easy to learn.