Draw it. Every time.
Blood relation questions are easy when drawn and very hard when held in the head. The two marks you lose here are almost always from trying to reason in words.
Use one notation and stick to it.
- Put people from the same generation on the same horizontal line.
- Put a parent above and a child below, joined by a vertical line.
- Mark a male with
+and a female with-next to the name. - Mark a married couple with a double line between them.
- Put a
?on the person the question asks about.
Relations you must be able to name
| Description | Relation |
|---|---|
| Father's or mother's brother | Uncle |
| Father's or mother's sister | Aunt |
| Brother's or sister's son | Nephew |
| Brother's or sister's daughter | Niece |
| Uncle's or aunt's child | Cousin |
| Father's father, mother's father | Grandfather |
| Wife's or husband's brother | Brother-in-law |
| Son's wife | Daughter-in-law |
Cousin has no gender in English, though papers written in Indian English do offer "cousin brother" as an option.
Do not assume gender from a name. In these puzzles A, B, C carry no gender unless the question states it or uses "he", "she", "son", "daughter", "wife" or "husband". Many questions are designed so the answer is undecidable without a stated gender, and "cannot be determined" is a real option.
Photograph and self-reference questions
"Pointing to a photograph, a man said..." These are solved by working from the inside out, that is, from the innermost phrase back to the speaker.
The two phrases that trip everyone up:
- "the only son of my father" = the speaker himself, if the speaker is male
- "the only daughter of my mother" = the speaker herself, if the speaker is female
Read the sentence from the last words backwards, replacing each phrase with a single person before moving outward.
Worked problem 1
Pointing to a photograph, a man said, "He is the son of the only son of my father." How is the person in the photograph related to the man?
Innermost phrase first: "the only son of my father".
The speaker is a man. His father's only son can only be the speaker himself. Replace that phrase with "me".
The sentence becomes: "He is the son of me."
The person in the photograph is the man's son.
Worked problem 2
A is the brother of B. C is the mother of A. D is the father of C. E is the mother of D. How is A related to D?
Take the statements one at a time and build the drawing.
- A is the brother of B → A and B are on the same line, same generation.
- C is the mother of A → C sits one line above A, joined to A. C is female.
- D is the father of C → D sits one line above C. D is male.
- E is the mother of D → E sits one line above D. This does not affect the question, but write it anyway.
Now count the generations from D downwards.
D is C's father. C is A's mother. So D is A's mother's father, which makes D A's maternal grandfather.
The question asked how A is related to D, so the answer is the other way round: A is D's grandson, if A is male.
A is described as "the brother of B", which tells us A is male. So A is D's grandson.
Always re-read the direction of the question at the end. Half the marks lost in this topic are from giving the correct relationship backwards — answering "grandfather" when the question asked how A is related to D.
Worked problem 3
Pointing to a lady in a photograph, Rahul said, "She is the daughter of the only daughter of my grandmother." How is the lady related to Rahul?
Work from the inside out again.
Innermost: "the only daughter of my grandmother".
Rahul's grandmother's only daughter is Rahul's mother or Rahul's aunt. But if the grandmother has only one daughter and that daughter is Rahul's aunt, then Rahul's own parent in that line would be a son. Standard exam convention takes the maternal grandmother, so her only daughter is Rahul's mother.
Replace the phrase: "She is the daughter of my mother."
The daughter of Rahul's mother is Rahul's sister.
Coded relation questions
Some papers use symbols instead of words:
A + Bmeans A is the father of BA - Bmeans A is the wife of BA * Bmeans A is the brother of BA / Bmeans A is the mother of B
Decode symbol by symbol into your usual drawing, then read the answer off the diagram. The key changes between papers, so copy it down first.