The questions you will find in the Stage 2 math test are quite similar to those used in typical management graduate jobs, with data interpretation and arithmetic-based questions. These are all mathematically very simple but often very tedious. You will be given a pencil and paper, and asked to do the test on a computer screen. The test is made of 30 MC questions, each question with 16 possible answers. There is one graph/scenario for every 4 questions.
Numeric
Have a look at the link for an idea of what to expect. The actual questions in the Cathay test are harder though. I found it better to read the questions first, then reading the information provided in the scenario to solve them. Don't hesitate to move on if you're not sure of how to solve a problem.
You can buy or borrow some books that are dedicated towards training people for numerical aptitude tests, which usually have a variety of useful exercises in them. Back in my day, I also did some GMAT questions to get my brain into gear. Just keep your cool and do your best, and let Cathay decide everything else. Good luck!