They contain all the concepts in detail from basics to the core. They give you a better understanding of each and every concept. And also the Brain Storming Questions and Objective Questions, given at the end of every chapter are very much helpful in analysing and understanding the questioning pattern in various entrance exams.
However, the standard of the questions given in the books are a bit low compared to other references. If you are in the view of gaining concept, these books would be the best, but if you need numericals and questions of greater standard,then this wouldn’t be of a very great use.
If you need greater view and wide range of questions of all standards, then its better you opt for Balaji Publications or Arihant, where you would find maximum no. Of questions and minimum concept.