If you're a high schooler studying in 8 th ,9 th or 10 th , you definitely know R.D. Sharma's books for your math queries. R.D. Sharma is a cult favourite of both teachers and students for many justified reasons. Even when I was in class 10 th , I treated my math R.D. Sharma as a bible and I wasn't a very bright student in math, yet, because of the book I managed to score well in my boards.