UPSC Prelims 2018 · CSAT
Question 72: Logical Reasoning and Mental Ability
Lakshmi, her brother, her daughter and her son are badminton players. A game of doubles is about to begin :
- (i)Lakshmi's brother is directly across the net from her daughter.
- (ii)Her son is diagonally across the net from the worst player's sibling.
- (iii)The best player and the worst player are on the same side of the net.
Who is the best player?
AnswerUPSC’s answer is (a).
Place the four players on a doubles court. The brother and the daughter face each other across the net, so Lakshmi and her son take the other two spots, one on each side. If the son stands on the brother's side, his diagonal opponent is the daughter, whose only sibling is the son, so the son is the worst player and the brother, on his side, is best. If the son stands on the daughter's side, his diagonal opponent is the brother, whose sibling is Lakshmi, so Lakshmi is worst and shares a side with the brother, who is again best.
Why each option is right or wrong
- (a) Correct: both layouts make the brother the best player.
- (b) The daughter is on the opposite side from the worst player in both layouts.
- (c) He is either the worst player or on the wrong side.
- (d) She is either on the wrong side or the worst player herself.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2018, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.