A said to B: “The woman I met yesterday at the park was the only daughter of the father of your brother.” How is the woman related to B?
- (a)Sister
- (b)Cousin
- (c)Mother
- (d)Aunt
Answer
Why
Correct — A. Shorten the phrase from B's side.
Rule: the father of your brother is your father.
So the woman is "the only daughter of B's father": a daughter of B's own parents, in B's generation.
A met her at the park, so she is a person other than B. She is B's sister, option (a).
Why the others are wrong
- (b)Cousin — A cousin is the daughter of B's uncle or aunt. This woman is the daughter of B's own father, which makes her B's sister.
- (c)Mother — B's mother is his father's wife, not his father's daughter. The statement places the woman in B's own generation.
- (d)Aunt — A paternal aunt is the daughter of B's grandfather. This woman is the daughter of B's father, one generation lower.
Concept
"The father of your brother" collapses to one person: B and B's brother share a father, so it is B's own father.
That leaves "the only daughter of B's father", a woman born to B's parents: B's sister.
The word only also fixes B's gender. If B were a woman, she would be her father's only daughter and the phrase would name B herself. The woman A met is someone else, so B is a son of that father.
The item treats B's brother's father as B's father. No step-parent is mentioned, and the options leave no room for one.
Key facts
- Your brother's father is your father.
- Your father's daughter is your sister, or you if you are female.
- Because she is the only daughter, the woman A met is B's one sister.
Study next
Common traps
- Answering for A instead of B, when the phrase is built from B's side ("your brother").
- Treating "the father of your brother" as a new man, when he is B's own father.
The same collapse to a parent decides 17 Sep 2025, 16:00, Reasoning Q.22, where "the daughter of the only child of my grandfather" is Jay's sister.
At 14 Sep 2025, 12:30, Reasoning Q.21, "the only daughter of my mother's father" is Seema's mother, which makes the man her brother.
Related PYQs
No directly related past PYQ was found.