Blood-relation puzzles are easy to picture and hard to track mentally. Build a tiny family tree as you read: a horizontal line for couples and siblings, a vertical line for parent-to-child.
Family-tree rules
Mark gender as you go: a small + for male, − for female. Generations stack top to bottom — grandparents on top, children below. Translate the final question into the diagram, then read off the answer.
- Mark gender as you go: a small + for male, − for female.
- Generations stack top to bottom — grandparents on top, children below.
- Translate the final question into the diagram, then read off the answer.
How to Approach It
- Sketch the tree as you read — Build a family tree while reading: a vertical line for parent-to-child and a horizontal line for couples and siblings, marking gender with + and −. The drawing does the remembering for you.
- Resolve one link at a time — Translate the relationship outward from the speaker, a single step at a time, rather than trying to leap the entire chain at once.
- Respect the clue words — 'Only son' or 'only daughter' pins down a specific person, and 'in-law' signals a marriage link rather than a blood one. These words change the answer.
- Read the answer off the diagram — Once the tree is complete, the required relationship is just the path between two people. Trace it and name it directly.
Techniques & Methods
- Draw the family tree — Use + for male, − for female; vertical lines for parent-to-child.
- Resolve outward, one link at a time — Translate the chain step by step from the speaker. e.g. 'mother's brother' → maternal uncle.
- Mind the word 'only' — 'Only son / only daughter' usually pins a specific person.
- In-laws are marriage lines — Keep relations by marriage separate from blood relations on the tree.
The Edge
Resolve relationships from the speaker outward, one link at a time. "My mother's brother's wife" becomes mother → her brother (my uncle) → his wife = aunt. Never try to leap the whole chain in one jump. Watch the word only — "my father's only son" usually means the speaker himself, which flips many answers.Worked example
A's mother is the sister of B's father. How is A related to B?
- Draw the link: A's mother and B's father are sister and brother — that is, siblings.
- That makes A's mother the aunt of B, and B's father the uncle of A.
- The children of two siblings are cousins to one another.
- So A and B are cousins.
Answer: A and B are cousins
Worked example
Pointing to a man, Reena says, 'He is the son of my grandfather's only son.' How is the man related to Reena?
- Work from the inside out. 'My grandfather's only son' — the single son of Reena's grandfather — must be Reena's own father.
- So the man is 'the son of Reena's father'.
- A son of her father is Reena's brother.
- Hence the man is Reena's brother.
Answer: He is Reena's brother
Worked Drills
Worked example
A is B's brother, C is A's mother, D is C's father. How is A related to D? (a) grandson b) granddaughter c) son d) great-grandson)
- C is A's mother and D is C's father, so D is A's mother's father.
- A's mother's father is A's (maternal) grandfather.
- So A is D's grandson.
Answer: grandson — option a)
Worked example
If 'P × Q' means P is the mother of Q, 'P + Q' means P is the father of Q, and 'P − Q' means P is the sister of Q, then in 'A + B − C × D', how is A related to D? (a) paternal grandfather b) maternal grandfather c) father d) uncle)
- A + B: A is the father of B. B − C: B is the sister of C, so A is also the father of C.
- C × D: C is the mother of D.
- A is the father of C, and C is the mother of D — so A is D's maternal grandfather.
Answer: maternal grandfather — option b)
Worked example
Pointing to a woman, a man says, 'Her father is the only son of my father.' How is the woman related to the man? (a) daughter b) sister c) niece d) mother)
- 'The only son of my father' is the man himself.
- So the woman's father is the man.
- That makes the woman his daughter.
Answer: daughter — option a)
Worked example
A and B are siblings. C is A's son and D is B's daughter. C and D are: (a) siblings b) cousins c) uncle and niece d) brother and sister)
- A and B are siblings.
- C is the child of A and D is the child of B.
- Children of two siblings are cousins.
Answer: cousins — option b)
Worked example
X is the brother of the son of Y's son. How is X related to Y? (a) son b) grandson c) nephew d) brother)
- Y's son's son is Y's grandson.
- X is the brother of that grandson — so X is also a child of Y's son.
- Therefore X is Y's grandson.
Answer: grandson — option b)
Worked example
Reena's mother's brother's wife is Reena's: (a) aunt b) mother c) cousin d) grandmother)
- Mother's brother is Reena's maternal uncle.
- His wife is married into that relation.
- The uncle's wife is Reena's aunt.
Answer: aunt — option a)
Worked example
P is the mother of Q; Q is the daughter of R. R is P's: (a) son b) brother c) husband d) father)
- Q is the daughter of both P and R.
- Two people who are both parents of the same child are a married couple.
- So R is P's husband.
Answer: husband — option c)
⚠ Watch out
- "In-law" relations come through marriage, not blood — keep them separate on the tree.
- The word only (only son / only daughter) is a strong clue, not filler.
- Maternal vs paternal matters when the question asks specifically.
Takeaways
- Draw the tree; never track the family purely in your head.
- Translate the chain one link at a time from the speaker outward.
- 'Only son/daughter' usually pins a single specific person.
- Two parents of the same child are a married couple — a fast inference.