Logical Reasoning · Lesson 3 of 13 · Updated ·
Blood Relations — Draw the Family Tree and Never Get Confused
Blood relation questions describe a family in words and ask how two people are related. Doing it in your head causes mistakes. Draw it.
1. The symbols
- Square = male, circle = female (or write + and −)
- Horizontal double line / orange line = married couple
- Vertical line = parent → child
- Same level = same generation (brothers, sisters, cousins)
In the picture: Ram and Sita are married; their children are Amit and Neha. Amit is married to Riya; their son is Kabir. So Kabir's grandfather is Ram, his aunt is Neha (father's sister), and his mother is Riya.
2. Relation names to know
| Relation | Meaning |
|---|---|
| Father's / mother's father | Grandfather |
| Father's brother | Uncle (chacha / tau) |
| Mother's brother | Uncle (mama) |
| Father's sister | Aunt (bua) |
| Brother's / sister's son | Nephew |
| Brother's / sister's daughter | Niece |
| Uncle's or aunt's child | Cousin |
| Wife's / husband's brother | Brother-in-law |
| Son's wife | Daughter-in-law |
| Only son of my father | Me (if I am male)! |
3. Solved examples
Example 1
A is the brother of B. B is the daughter of C. D is the father of C. How is A related to D?
Draw: D → C → (A, B). A is a male child of C, and C is a child of D → A is D's grandson.
Example 2 — the photograph
Pointing to a photograph, Raj says, "She is the daughter of my grandfather's only son." Who is she?
Grandfather's only son = Raj's father. Daughter of Raj's father = Raj's sister.
Trick: start from the end of the sentence ("my grandfather's only son") and work backwards to the person.
Example 3
Introducing a man, a woman says, "His mother is the only daughter of my mother." How is the woman related to the man?
Only daughter of my mother = the woman herself. So she is the man's mother.
Example 4 — gender unknown
P is the sibling of Q. Q is the son of R. How is P related to R?
P is R's child, but P's gender is not given → P is R's son or daughter (cannot be determined exactly). Options like "cannot be determined" are real answers.
4. Coded relations
A + B means A is the father of B; A − B means A is the wife of B; A × B means A is the brother of B; A ÷ B means A is the daughter of B.
Example 5
What does P × Q + R mean?
P is the brother of Q, and Q is the father of R → P is R's uncle (father's brother).
Example 6
Which expression means "M is the mother of N"?
We need M as N's mother: M − (father of N). So M − O + N means M is the wife of O, and O is the father of N → M is N's mother ✓.
Common mistakes
- Assuming gender from a name. If it is not stated, it is unknown.
- Reading the sentence from the front in photograph questions. Start from "my …" at the end.
- Forgetting that "only son" or "only daughter" often means the speaker or their parent.
Quick recap
- Square = male, circle = female, horizontal line = married, vertical line = child.
- Draw generation by generation.
- Photograph questions: decode from "my …" backwards.
- Don't assume gender.