All other from data interpretation and all it needs is huge practice and be quick in calculations. Learn first 25 number tables and square roots and cube roots. Practice as much as you can so that you can increase your calculation speed. Speed matters the most in the exam. \ \ So all the questions can be solved using basic knowledge and knowing the kind of questions which were being asked. \ So after knowing the basics get subscribed to any test series such as Mahendra . And solve as many mock papers papers as you can. All the best