Question

Introducing a girl, a boy said, "She is the daughter of the mother of my father's only son." How is the girl related to the boy?

• A. Sister
• B. Daughter
• C. Cousin
• D. Niece

Hint:

Strategy for solving blood relation problems:

• Break the sentence into smaller parts.
• Start from the \textbf{innermost relationship}.
• Replace phrases step-by-step until the relationship becomes clear.

Shortcut for this question: \[ \text{Father's only son} = \text{The boy himself} \] \[ \text{Mother of the boy} = \text{His mother} \] \[ \text{Daughter of his mother} = \text{His sister} \]

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
This is a blood relation problem. We need to decode the statement made by the boy to find his relationship with the girl.
Step 2: Key Formula or Approach:
The best way to solve such problems is to break down the statement from the end and work backwards, identifying each relationship relative to the speaker (the boy).
Step 3: Detailed Explanation:
Let's break down the statement: "She is the daughter of the mother of my father's only son."
1. Start with the innermost part: "my father's only son". Since the speaker is a boy, his father's only son must be the boy himself. (Assuming he has no brothers).
2. Now substitute this back into the statement: "the mother of the boy himself". The mother of the boy is, simply, his mother.
3. Substitute this again: "the daughter of my mother". The daughter of his mother is his sister.
Therefore, the statement simplifies to "She is my sister."
Step 4: Final Answer:
The girl is the boy's sister.