UPSC CSE Prelims 2025

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?

EXPLANATION

(4) The Question cannot be answered even using any of the Statements.

The relationship between Q and P cannot be definitively established even when both statements are considered together.

Statement I: "P has two sisters, R and S." This establishes P, R, and S as siblings. It provides no information about Q, rendering it insufficient alone to determine Q's relation to P.
Statement II: "R's father is the brother of Q." This indicates R's father and Q are siblings. It does not directly link P to Q, making it insufficient alone to determine Q's relation to P.
Combining Statement I and Statement II: From Statement I, P and R are siblings, sharing the same father. From Statement II, R's father (who is also P's father) is the brother of Q. This implies that Q is P's paternal uncle or paternal aunt. However, the gender of Q is not provided in either statement or their combination. Without this crucial information, the exact relationship between Q and P cannot be determined.

Option 1: "The Question can be answered by using one of the Statements alone, but cannot be answered using the other statement alone." This is incorrect because neither Statement I nor Statement II individually provides sufficient information to determine the relationship between Q and P.
Option 2: "The Question can be answered by using either Statement alone." This is incorrect. As explained, both statements individually are insufficient to establish the relationship between Q and P.
Option 3: "The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone." This is incorrect. While neither statement alone is sufficient, even combining both statements does not provide enough information to determine the exact relationship due to the unknown gender of Q.