Quantitative aptitude is a subject which now comes in almost every competitive exam, be it GATE, CAT, SSC, CDS, Bank Exams or any public service recruitment exam. There are lots of book available for Quantitative aptitude below are some of the best books.
1. Quantitative aptitude by R.S Agarwal
This is no doubt the most popular book, the book covers almost all concepts related to quantitative aptitude in detail. The quantity of questions in this book is quite high, but there are too many questions of similar kind, it feels like same questions are repeated with different numerical values. It also lacks shortcut methods of solving questions. This is a good book if you are beginning with aptitude.
2. How To Prepare For Quantitative Aptitude For The CAT by Arun Sharma
This is a very popular book among the CAT aspirants, even if you are not going to appear for CAT I suggest you to read this book. It has several short cut tricks that help solve the problems quickly.The exercise questions are also divided into three difficulty levels. If you are not a CAT aspirant then the first two levels are sufficient for you, for any exam other than CAT.
3. Quantitative Aptitude For Competitive Examinations by Abhijit Guha
This is a good book for building concepts of quantitative aptitude, it is useful both for beginners and also for those who want to brush up their skills in gaining speed and accuracy. The theory is provided in more detail comparing to other books. The new edition of this book contains 22 original test papers of various exams.