Let me start with the very basics, Soujany.
Firstly, you need practice the Math books of class 9th to 12th. Widely accepted practice makes a man perfect. You will need to practice a lot to improve your logic and handling on those type of questions. You need to understand that everyone studies but only few reaches to their goals that's because the time has come of smart work and not the hard work. You need to work smartly, in simple, try solving more and more math questions with your own way of using logic. That will surely help you out in improving your aptitude.
I find that the harder I work, the more luck I seem to have.