A question is given followed by two Statements I and II. Consider the Question and the Statements and mark the correct option. Question : How is Q related to P ? Statement I : P has two sisters, R and S. Statement II : R's father is the brother of Q. Which one of the following is correct in respect of the above Question and the Statements ?

(a) The Question can be answered by using one of the Statements alone, but cannot be answered using the other statement alone.
(b) The Question can be answered by using either Statement alone.
(c) The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone.
(d) The Question cannot be answered even using any of the Statements. ✓ UPSC's answer

Why the answer is (d)

• Statement I alone says nothing about Q, and Statement II alone says nothing about P, so neither alone can answer the question.

• Together: R is P's sister, and Q is a sibling of R's father — but Q's gender is not given, so Q is either a brother or a sister of that father.

• Even if P and R share the same father, Q would be P's paternal uncle or paternal aunt, and the statements do not say which.

• The word "sisters" also does not rule out half-sisters with different fathers, which would break the link altogether.

• So the relation cannot be fixed even with both statements — option (d).

Why the other options are wrong

(a) The Question can be answered by using one of the Statements alone, but cannot be answered…: Neither statement alone provides any link between Q and P, so the question cannot be answered by one statement alone.
(b) The Question can be answered by using either Statement alone.: Neither statement alone connects Q to P; Statement I has no mention of Q and Statement II has no mention of P, so the question is not answerable by either statement in isolation.
(c) The Question can be answered by using both the Statements together, but cannot be…: Even together, Q's gender is not given (uncle or aunt), and R need not share P's father, so Q's exact relation to P cannot be fixed.

Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2025, held on 25 May 2025. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.