Mithilesh said to Neha, "Your only brother's son is my wife's brother." In this blood relation question, how is Neha related to the wife of Mithilesh?

Introduction / Context:
This family relation puzzle uses a statement from Mithilesh to Neha about Neha's only brother and his son. The son is identified as Mithilesh's wife's brother, and we must determine how Neha is related to Mithilesh's wife. These questions test your ability to track relationships through both blood and marriage and identify roles like aunt and nephew correctly.

Given Data / Assumptions:
• Neha has exactly one brother.• The son of Neha's only brother is the person being discussed.• Mithilesh says that this son is his wife's brother.• A woman's brother is her sibling; they share the same parents.• The son of Neha's brother is Neha's nephew.

Concept / Approach:
Let Neha's only brother be B. Then B's son is S. From Mithilesh's statement, S is also the brother of Mithilesh's wife W. Since S is W's brother, the father of S and W must be the same person. We already know the father of S is B. Therefore, B is also the father of W, so W is a daughter of Neha's brother. That makes W the niece of Neha. Neha is then an aunt of W. So Neha is related to Mithilesh's wife as her aunt.

Step-by-Step Solution:
Step 1: Let B be Neha's only brother.Step 2: The son of B is S. So S is Neha's nephew (child of her brother).Step 3: Mithilesh says, "Your only brother's son is my wife's brother." So S is also the brother of Mithilesh's wife W.Step 4: If S is the brother of W, then S and W share the same parents.Step 5: Since S's father is B, W's father must also be B.Step 6: Therefore W is a daughter of B, making W another child of Neha's brother.Step 7: Any daughter or son of your brother is your niece or nephew. Thus W is Neha's niece, and Neha is W's aunt.

Verification / Alternative check:
Sketch a family tree with B as the central father figure for S and W. Above B are the parents shared by Neha and B. Neha is a sibling of B, which puts her in the same generation as B and one above S and W. That generational difference and shared ancestry establish that Neha is an aunt to S and W. Since W is Mithilesh's wife, this means Neha is the aunt of Mithilesh's wife. No information suggests Neha is the mother or sister of W, so aunt is the only accurate close relation.

Why Other Options Are Wrong:
Mother-in-law: Neha would be the mother-in-law of Mithilesh if she were the mother of W; but the father of W is Neha's brother, not Neha.Sister: Neha and W are one generation apart; W is her brother's daughter, not her sibling.Mother: No data indicates that Neha is the mother of S or W; instead, their father is B.Cousin: Cousins are in the same generation; here Neha is older than W and is in the generation above W.

Common Pitfalls:
Some candidates see that S is both Neha's nephew and Mithilesh's brother-in-law and become confused about how W fits in. The key is to recognise that the son of Neha's brother and the brother of Mithilesh's wife are the same person. Once that is clear, you can deduce that Mithilesh's wife must also be a child of Neha's brother, making her Neha's niece and Neha her aunt.

Final Answer:
Neha is the aunt of Mithilesh's wife.