UPSC Prelims 2013 · CSAT
Question 29: Logical Reasoning and Mental Ability
A, B, C, D and E belong to five different cities P, Q, R, S and T (not necessarily in that order). Each one of them comes from a different city. Further it is given that :
- 1.B and C do not belong to Q.
- 2.B and E do not belong to P and R.
- 3.A and C do not belong to R, S and T.
- 4.D and E do not belong to Q and T.
Which one of the following statements is not correct ?
AnswerUPSC’s answer is (d).
Clue 3 says A and C are not from R, S or T, and clue 1 says C is not from Q, so C is from P and A is from Q. Clue 2 leaves B and E out of P and R. Clue 4 removes Q and T from E, so E is from S. Then B, who cannot be from P, Q or R, is from T, and D is from R. Result: A-Q, B-T, C-P, D-R, E-S. So the statement that B belongs to S is incorrect.
- 1. Given: B and C are not from Q; with clue 3 this fixes C as P and A as Q.
- 2. Given: B and E are not from P or R; with clue 1, B is left with S or T.
- 3. Given: A and C are not from R, S or T, so A is P or Q and C is P.
- 4. Given: D and E are not from Q or T; this fixes E as S, B as T and D as R.
Why each option is right or wrong
- (a) Correct statement. C belongs to P.
- (b) Correct statement. D belongs to R.
- (c) Correct statement. A belongs to Q.
- (d) Not correct, so it is the answer. B belongs to T; S is E's city.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2013, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.