Episode 8 — Aptitude and Reasoning / 8.21 — Blood Relation
8.21.a Concepts and Formulas -- Blood Relation
1. Basic Family Relationship Terms
Generation Level 0 (Same Generation)
| Relationship | Meaning |
|---|---|
| Brother | Male sibling |
| Sister | Female sibling |
| Sibling | Brother or Sister |
| Cousin | Uncle's / Aunt's child |
| Husband | Male spouse |
| Wife | Female spouse |
| Brother-in-law | Spouse's brother OR Sister's husband |
| Sister-in-law | Spouse's sister OR Brother's wife |
Generation Level +1 (One Generation Above)
| Relationship | Meaning |
|---|---|
| Father | Male parent |
| Mother | Female parent |
| Uncle (Paternal) | Father's brother |
| Aunt (Paternal) | Father's sister |
| Uncle (Maternal) | Mother's brother (Mama) |
| Aunt (Maternal) | Mother's sister (Mausi) |
| Father-in-law | Spouse's father |
| Mother-in-law | Spouse's mother |
Generation Level +2 (Two Generations Above)
| Relationship | Meaning |
|---|---|
| Grandfather (Paternal) | Father's father |
| Grandmother (Paternal) | Father's mother |
| Grandfather (Maternal) | Mother's father |
| Grandmother (Maternal) | Mother's mother |
Generation Level -1 (One Generation Below)
| Relationship | Meaning |
|---|---|
| Son | Male child |
| Daughter | Female child |
| Nephew | Brother's/Sister's son |
| Niece | Brother's/Sister's daughter |
| Son-in-law | Daughter's husband |
| Daughter-in-law | Son's wife |
Generation Level -2 (Two Generations Below)
| Relationship | Meaning |
|---|---|
| Grandson | Son's/Daughter's son |
| Granddaughter | Son's/Daughter's daughter |
2. Paternal vs. Maternal Relationships
Paternal Side (Father's Side)
Paternal Grandfather --- Paternal Grandmother
|
------+------------------+
| |
Father --- Mother Paternal Uncle/Aunt
|
YOU
| Hindi Term | English | Relation |
|---|---|---|
| Dada/Dadi | Paternal Grandfather/Grandmother | Father's parents |
| Chacha/Chachi | Paternal Uncle/Aunt | Father's younger brother & wife |
| Tauji/Taiji | Paternal Uncle/Aunt | Father's elder brother & wife |
| Bua/Fufa | Paternal Aunt/Uncle | Father's sister & husband |
Maternal Side (Mother's Side)
Maternal Grandfather --- Maternal Grandmother
|
------+------------------+
| |
Mother --- Father Maternal Uncle/Aunt
|
YOU
| Hindi Term | English | Relation |
|---|---|---|
| Nana/Nani | Maternal Grandfather/Grandmother | Mother's parents |
| Mama/Mami | Maternal Uncle/Aunt | Mother's brother & wife |
| Mausi/Mausa | Maternal Aunt/Uncle | Mother's sister & husband |
3. Family Tree Notation (Standard Symbols)
When constructing family trees, use these conventions:
SYMBOLS:
Male: M or use the name directly
Female: F or use the name directly
Marriage: ---- (horizontal line between spouses)
A ---- B (A is married to B)
Parent-Child: | (vertical line)
A ---- B
|
C (C is child of A and B)
Siblings: Connected to same parent line
A ---- B
|
+----+----+
| | |
C D E (C, D, E are siblings)
Generation: Same generation = same horizontal level
Example Family Tree
Grandfather ---- Grandmother
|
+--------+--------+
| |
Father ---- Mother Uncle ---- Aunt
| |
+--+--+ +--+--+
| | | |
YOU Sister Cousin1 Cousin2
4. Generation Levels and Counting
Generation +2: Grandparents
Generation +1: Parents, Uncles, Aunts
Generation 0: You, Siblings, Cousins, Spouse
Generation -1: Children, Nephews, Nieces
Generation -2: Grandchildren
Rule: To find the relationship between two people:
- Find both people on the family tree.
- Count the generation difference.
- Determine the path (paternal/maternal, direct/through marriage).
5. Common Relationship Phrases (Exam Language)
These phrases are frequently used in exam questions. Learn to decode them:
| Phrase | Decoded Meaning |
|---|---|
| "A is the son of B" | B is A's parent (father or mother) |
| "A is the father of B's sister" | A is B's father |
| "A is the brother of B's father" | A is B's uncle (paternal) |
| "A's mother is B's mother-in-law" | B is married to A (or A's sibling) |
| "A is the only son of B's father" | A = B (if B is male) or A is B's brother (only brother) |
| "A's father's wife" | A's mother |
| "A's mother's husband" | A's father |
| "A's brother's father" | A's father |
| "A's father's only daughter" | A herself (if A is the only daughter) |
| "A's mother's only son" | A himself (if A is the only son) |
| "Son of my grandfather" | My father or my uncle |
| "Daughter of my grandmother" | My mother or my aunt |
| "Only child of my parents" | Myself |
| "A introduced B as his mother's husband's mother" | B is A's paternal grandmother |
6. "Only" Keyword -- Critical Concept
The word "only" is very important in blood relation problems:
| Statement | Meaning |
|---|---|
| "A is the only son of B" | B has no other sons; A is the sole son |
| "A is the only child of B" | B has exactly one child = A |
| "A has only two children" | A has exactly 2 children, no more |
| "A is the only daughter of B's father" | A is B's sister (and B's father has only one daughter) |
7. Pointing to a Photograph -- Problem Type
This is the most common exam question format:
"Pointing to a photograph, A says, 'He/She is the _____ of my _____.' How is the person in the photograph related to A?"
Solving Approach:
- Identify the gender of the person in the photograph (He/She).
- Trace the relationship chain step by step.
- Build a mini family tree.
- Determine the final relationship.
Example:
"Pointing to a photo, Rahul says, 'She is the daughter of my grandfather's only son.'"
Step 1: Grandfather's only son = Rahul's father (assuming Rahul's grandfather has only one son). Step 2: Daughter of Rahul's father = Rahul's sister.
Answer: The person is Rahul's sister.
8. Coded Relationship Problems
In these problems, relationships are represented by symbols:
Example Code System:
A + B means "A is the father of B"
A - B means "A is the mother of B"
A * B means "A is the brother of B"
A / B means "A is the sister of B"
A = B means "A is the spouse of B"
Solving Approach:
- Write down the code meanings.
- Replace symbols with relationships.
- Build the family tree step by step.
Example:
If P + Q - R means "P is the father of Q, Q is the mother of R," how is P related to R?
P (father) ---- Q (mother)
|
R (child)
Wait -- "P + Q" means P is father of Q, and "Q - R" means Q is mother of R. So P is Q's father, and Q is R's mother. Therefore P is R's maternal grandfather.
9. Relationship Through Marriage (In-Laws)
In-Law Relationships:
Your Spouse's Father = Father-in-law
Your Spouse's Mother = Mother-in-law
Your Spouse's Brother = Brother-in-law
Your Spouse's Sister = Sister-in-law
Your Son's Wife = Daughter-in-law
Your Daughter's Husband = Son-in-law
Your Brother's Wife = Sister-in-law (Bhabhi)
Your Sister's Husband = Brother-in-law (Jija)
Key Insight:
In-law relationships connect two families through marriage. When tracing through an in-law, you "jump" from one family tree to another.
10. Dual Relationships
Sometimes a person can be related through two different paths:
Example:
If two siblings marry two siblings:
Family 1: A (brother) --- C (wife, from Family 2)
B (sister) --- D (husband, from Family 2)
Family 2: C (sister) --- A (husband, from Family 1)
D (brother) --- B (wife, from Family 1)
Now D is:
- A's brother-in-law (wife's brother)
- A's sister's husband (also brother-in-law)
Both paths give the same relationship!
11. Gender Identification Rules
| Word | Gender |
|---|---|
| Father, Son, Brother, Uncle, Nephew, Grandfather, Husband, Son-in-law, Brother-in-law | Male |
| Mother, Daughter, Sister, Aunt, Niece, Grandmother, Wife, Daughter-in-law, Sister-in-law | Female |
| Cousin, Sibling, Child, Parent, Spouse | Gender Neutral |
Important:
- "Cousin" does NOT indicate gender. A cousin can be male or female.
- "Child" does NOT indicate gender. Need additional info.
- "Parent" does NOT indicate gender. Could be father or mother.
- "Sibling" does NOT indicate gender. Could be brother or sister.
12. Key Formulas / Rules
Rule 1: Only One Couple
If a question mentions "only son" or "only daughter," there is typically one couple at each generation level.
Rule 2: Tracing Path
To find the relationship of X to Y:
- Start from Y.
- Trace the path to X.
- At each step, note the relationship.
- Combine the relationships.
Rule 3: Common Tricky Equivalences
Father's or Mother's son = Brother (or self)
Father's or Mother's daughter = Sister (or self)
Father's father = Grandfather (paternal)
Mother's father = Grandfather (maternal)
Father's brother's son = Cousin
Mother's sister's daughter = Cousin
Father's mother = Grandmother (paternal)
Mother's mother = Grandmother (maternal)
Son's wife = Daughter-in-law
Daughter's husband = Son-in-law
Wife's/Husband's father = Father-in-law
Wife's/Husband's mother = Mother-in-law
Wife's/Husband's brother = Brother-in-law
Wife's/Husband's sister = Sister-in-law