Dear aspirant,

Solving previous year questions is a very good preparation practice as it will definitely help you get familiarity with the type of questions asked in the exam. If you are preparing for mains now and are short of time, please don't bother solving the section 2 questions right now. Make yourself comfortable with the concepts and do JEE mains questions. But, if you are preparing for advanced and have like a l year before the exam do both the sections as and when you finish each topic. It all depends on what your goals are, so look at how much time you have and plan accordingly.