My brother is an iitian he prefferd me to follow rd sharma .then from 10th onwards till the intermediate completion I used rd sharma for maths.it is an excellent maths book having sufficient examples with important notes and details explanation about the subject .moreover it has difficult exercises both useful for ncert as well as for competative exams using which one can succesfully write any of exams.its key has almost nil wrong answers along with hint provided for very difficult program .moreover it is avaiable at avg price.so I would like to advice to follow this for clearance of concepts which is best for students.