RAS question
Introducing a man, a woman says, 'His mother is the only daughter of my mother.' How is the woman related to the man?
Correct answer: (D) Mother.
The woman is the man's mother because his mother is the only daughter of the woman's mother, which can only be the woman herself.
Explanation
This is a blood-relation question that has to be read backwards. The statement says, "His mother is the only daughter of my mother." The source explains that in such pointing-to-a-person problems, the useful method is to trace the statement backwards. Start with "my mother": it refers to the woman's mother. That mother has only one daughter. Since the speaker is a woman, that only daughter is the speaker herself. Therefore, the man's mother is the woman who is speaking. So the relationship is not indirect through a sibling or an older generation; it is direct: the woman is the man's mother.
Why the other options are wrong
- (A) Sister would require the woman and the man to share a parent, but the statement identifies the woman as the man's mother.
- (B) Aunt would fit only if the man's mother were the woman's sister, but the phrase "the only daughter of my mother" points to the woman herself.
- (C) Grandmother would require the woman to be the mother of the man's mother, whereas the statement makes the woman the man's mother.
Concept
This tests blood-relation reasoning, especially pronoun anchoring and backward tracing in pointing-to-a-person questions. It recurs in RAS reasoning because a short family statement can change meaning completely if "my", "his" and "only daughter" are not resolved precisely.