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

Concept:
Blood relation questions require careful interpretation of family relationships described in a statement. The best approach is to simplify the statement step-by-step and identify each relationship logically.
Step 1: Start with the innermost part of the sentence.
The statement says: \[ \text{"my father's only son"} \] Since the boy himself is speaking, the phrase "my father's only son" refers to the boy himself.
Step 2: Identify the next relation.
The sentence now becomes: \[ \text{"the mother of my father's only son"} \] Since the father's only son is the boy, the mother of the boy is simply his mother.
Step 3: Interpret the complete statement.
The girl is described as: \[ \text{"the daughter of my mother"} \] The daughter of the boy's mother would be:

• Either the boy himself (if he were a girl) or
• His sister

Since the statement refers to a girl, the relationship must be: \[ Sister \]
Step 4: Final answer.
\[ \boxed{\text{Sister}} \]