UPSC Prelims 2014 · CSAT
Question 21: Logical Reasoning and Mental Ability
Six books are labelled A, B, C, D, E and F and are placed side by side. Books B, C, E and F have green covers while others have yellow covers. Books A, B and D are new while the rest are old volumes. Books A, B and C are law reports while the rest are medical extracts. Which two books are old medical extracts and have green covers ?
AnswerUPSC’s answer is (b).
Filter the books by each property. Green covers: B, C, E, F. Old volumes: C, E, F (A, B and D are new). Medical extracts: D, E, F (A, B and C are law reports). A book that is green, old and medical must satisfy all three lists, which leaves E and F. C is green and old but is a law report; D is medical but yellow and new.
Why each option is right or wrong
- (a) B is new and a law report.
- (b) Right. E and F are green, old and medical.
- (c) C is a law report, so it fails the medical test.
- (d) C is a law report, so the pair fails the medical test.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2014, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.