UPSC Prelims 2013 · CSAT
Question 30: Logical Reasoning and Mental Ability
Seven men, A, B, C, D, E, F and G are standing in a queue in that order. Each one is wearing a cap of a different colour like violet, indigo, blue, green, yellow, orange and red. D is able to see in front of him green and blue, but not violet. E can see violet and yellow, but not red. G can see caps of all colours other than orange. If E is wearing an indigo coloured cap, then the colour of the cap worn by F is
AnswerUPSC’s answer is (c).
G sees every colour except orange, so G wears orange. D, who sees A, B and C, sees green and blue but not violet, so those three hold green and blue and no violet. E sees violet and yellow in front of him but not red. Violet must be among A to D but not A to C, so D is violet. Then yellow must be among A to C, so A, B and C wear green, blue and yellow in some order. E is indigo and G orange, so F is red.
Why each option is right or wrong
- (a) Wrong. Blue is worn by one of A, B or C.
- (b) Wrong. Violet is worn by D.
- (c) Right. Red is the only colour left for F.
- (d) Wrong. Orange is worn by G.
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.