Quantitative aptitude by R.S Aggarwal is a book which deals withe various aspects of aptitude generally asked in competitive exams in India. This book contains almost all the syllabus related to exams like Bank clerk, PO, SSC, Railways etc. But concepts are not dealt in detail. So student face some problem in understanding. Examples are also not much in this book.
But question in exercise are given in ample amount. Each and every type of question is given there which are asked in competitive exams. So if you practice this book thoroughly, you can certainly crack the exams. So overall this is a good book but can be made better.