It is best book for preparing competitive exams like ssc, upsc, state pscs, cat etc. I know many people who scored good marks in ssc & cat using this book. It is helpful for any age group. The language of this book is very is to understand.
But one thing you should note about this book that you must be consistent to get maximum benefit from this book. You must try this book. Give this precious gift to your childrens and relatives.