Key features this series is focused on the quantitative section of the CSAT paper ii balanced coverage of theory with a CSAT-focused approach section tests providing ample practice questions about the book: csat paper ii numerical aptitude and data interpretation the CSAT series by Nishit K Sinha helps students deal with the new examination pattern introduced by the upsc. This series incorporates all the essential changes introduced in the syllabus of the preliminary examination. It provides a conceptual approach to many new fields and focuses on these new key areas for the benefit of the students. While volume 1 of this series covers various aspects of number system, volume 2 offers an insightful study on data interpretation,data sufficiency, arithmetic and geometry. Meticulous explanation of these concepts followed by ample practice questions will help students prepare well and perform to the best of their capability.