Yes, if you want to do well in CBSE Class 12 Mathematics, you need to do solutions and sample papers. Once you know the basics of the subject, you should start taking practise tests to see how long it takes you to solve each problem. These manual papers are a helpful way to learn how the marks will be split, what kinds of questions will be asked, and how the exams are set up. But perhaps the most important thing about the papers is that they help students figure out how to divide their time between questions.