Blood Relations

Core Approach

Always draw a family tree as you read — never try to solve blood relation puzzles mentally. Use symbols: + for male, - for female, = for marriage, | for parent-child link.

Key Relationship Glossary

• Mother's/Father's brother = Uncle (maternal/paternal)
• Mother's/Father's sister = Aunt (maternal/paternal)
• Father's sister's son/daughter = Cousin
• Son's wife = Daughter-in-law; Daughter's husband = Son-in-law
• Brother's son/daughter = Nephew/Niece
• Father's father = Grandfather; Mother's mother = Grandmother
• Spouse's sibling = Brother-in-law / Sister-in-law
• Sibling's spouse = Brother-in-law / Sister-in-law (same terms, different relation)

Worked Examples

1. "A is B's father. B is C's sister. How is A related to C?" → A is B's father, B and C are siblings → A is C's father

2. "A is B's son. C is A's sister. How is C related to B?" → A and C are siblings, A is B's son, so C is also B's child → C is B's daughter

3. "Pointing to a photo, Rahul said, 'She is the daughter of my grandfather's only son.'" How is the woman related to Rahul?

   → Grandfather's only son = Rahul's father → the woman is father's daughter → She is Rahul's sister

4. "A is B's father. B is C's mother. D is C's brother." How is D related to A? → D is C's sibling, C is B's child, B is A's child → D is A's grandchild (grandson)

Drill

1. "A is B's mother. C is B's son. How is A related to C?" — Grandmother
2. "P is Q's father. Q is R's sister. How is P related to R?" — Father
3. "Pointing to a man, a woman says 'His mother is the only daughter of my mother.' How is the woman related to the man?" — Mother (she IS the man's mother, since she's her own mother's only daughter)
4. "X's father is Y's son. X has no siblings. What is the relation between Y and X?" — Grandfather (Y is X's grandfather)
5. "A is B's brother. C is A's mother. D is C's father. How is B related to D?" — Grandchild (grandson/granddaughter)

Practice tracker

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