Q. 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.
Correct Answer : d)
UPSC Prelims 2025 CSAT
Explanation :
Assess Statement I alone:
I. “P has two sisters, R and S.”
– This tells us P’s siblings but nothing about Q.
⇒ Statement I alone is insufficient.
Assess Statement II alone:
II. “R’s father is the brother of Q.”
– R’s father is also P’s father (since R is P’s sister).
– So P’s father is the brother of Q ⇒ Q is a sibling of P’s father ⇒ Q is either P’s paternal uncle or paternal aunt.
– But we do not know Q’s gender ⇒ cannot decide uncle vs. aunt.
⇒ Statement II alone is insufficient to pin down the exact relationship.
Combine I and II:
– I only tells us R and S are sisters of P; II tells us Q is a sibling of their father.
– Even together, Q could be male or female ⇒ still “paternal uncle / aunt” ambiguous.
⇒ Both statements together remain insufficient to give a definite single relationship.
Therefore, the question cannot be answered even using any of the statements.
Correct option: (d).