UPSC Prelims 2026 CSAT Paper II · Q44 of 70 Logical Reasoning medium

P has a son and a daughter. S is the mother of T. S is R's spouse. Q and R are children of P. Then how is Q related to S?

  1. (a) Q is a sister of S
  2. (b) Q is a daughter of S
  3. (c) Q is the mother of S
  4. (d) Q is a sister of the husband of S ✓ UPSC's answer

Why the answer is (d)

• P has two children, Q and R, making Q and R siblings.

• S is R's spouse, which means S is married to R.

• Since Q is R's sibling, Q is the brother or sister of R.

• Therefore, Q is the sibling of S's husband (R).

• This relationship makes Q the sister (or brother) of the husband of S, matching option (d).

Why the other options are wrong

(a) Q is a sister of S
Q is a sibling of R, not S, so Q cannot be S's sister.
(b) Q is a daughter of S
Q is a child of P, while S is R's spouse, so Q is not S's daughter.
(c) Q is the mother of S
Q is a child of P, making Q a generation below S's parents, so Q cannot be S's mother.

Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2026, held on 24 May 2026. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.

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