Mathematics is not very difficult, and there is no particularly difficult Olympic math problem.
I'm in high school now. When I took the junior high school entrance exam, I remember that I missed two full marks in mathematics, or it was simply addition and subtraction. Chinese then asked me to write a composition; English is not very difficult, and I seem to have only one or two points.
Each subject has several sets of test papers, so that several people will not copy the answers in one classroom. Some people say that the volume 1 is the simplest, and I think it should not be too different.
And the admission criteria are not so strict. It's not that you can only go at 100, but you can reach 70% and 75%.
So don't worry ~ ~ As long as you study well now, you should be able to climb the maple leaf. However, we should not take it lightly. I also saw some people who failed the exam, but they were all poor.