Blood Relations

🟢 Lite — Quick Review (1h–1d)

Rapid summary for last-minute revision before your exam.

Blood Relations questions test your understanding of family relationships. In SSC CGL Tier 1, 1-2 questions appear from this topic. The key is to carefully decode relationship words and build a family tree diagram.

Essential Relationship Terms:

Term	Meaning
Father/Mother	Parents
Son/Daughter	Children
Brother/Sister	Siblings
Grandfather/Grandmother	Parents of parents
Uncle/Aunt	Sibling of parent
Nephew/Niece	Child of sibling
Cousin	Child of uncle/aunt
Husband/Wife	Spouses
Father-in-law/Mother-in-law	Spouse’s parents

⚡ SSC CGL Exam Tips:

• “Maternal” = mother’s side; “Paternal” = father’s side
• “Only” narrows the relationship (only son = no other sons)
• “A is B’s brother” — unless stated otherwise, they’re siblings sharing both parents
• Draw a family tree diagram for complex relations
• “Married to” = spouse; “Daughter of A’s mother” = A themselves or sibling?

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🟡 Standard — Regular Study (2d–2mo)

Standard content for students with a few days to months.

Understanding Blood Relations with Examples

Example 1: Direct Relationship Pointing to a man, a woman said, “His mother is the only daughter of my mother.” How is the woman related to the man?

Solution:

• “Only daughter of my mother” = the woman herself (she’s the only daughter)
• So the woman is the mother of the man Answer: Mother ✓

Example 2: Generation Gap A is B’s sister. B is C’s father. D is C’s mother. What is A’s relation to D?

Family tree:

• B is C’s father → B is parent of C
• D is C’s mother → D is parent of C
• Therefore B and D are spouses
• A is B’s sister → A is D’s sister-in-law (A’s sibling is married to D)

Wait: A and B are siblings. If B is married to D, then A is D’s sister-in-law.

Actually: A (female) is sister of B (male). B is married to D (female). So A is D’s sister-in-law. (A is the sister of D’s husband)

Answer: Sister-in-law ✓

Example 3: Multiple Relations If P is Q’s mother, R is P’s brother, and S is R’s son, how is P related to S?

Family tree:

• P is Q’s mother → Q is child of P
• R is P’s brother → R is sibling of P (male)
• S is R’s son → S is child of R P is Q’s mother and P’s brother R has son S. So S is P’s nephew (child of P’s sibling).

Answer: Nephew ✓

Key Relationship Chains:

Relationship	Generation
Grandparent	+2 generations
Parent	+1 generation
Sibling	Same generation
Aunt/Uncle	Same generation as parent
Niece/Nephew	-1 generation
Cousin	Same generation as niece/nephew’s parent

⚠️ SSC CGL Common Mistakes:

1. Getting confused by gender-specific terms
2. Not distinguishing between maternal and paternal sides
3. Missing that “only” eliminates other possibilities
4. Forgetting that siblings share at least one parent

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🔴 Extended — Deep Study (3mo+)

Comprehensive coverage with complex family trees and previous year SSC CGL patterns.

Complex Blood Relation Problems:

Example 1: Chained Relationships Introducing a boy, a girl said, “He is the son of my mother’s brother.” How is the boy related to the girl?

Solution:

• “My mother’s brother” = maternal uncle
• “Son of my mother’s brother” = maternal cousin (specifically, son of maternal uncle)
• The boy could also be the girl’s brother if the maternal uncle is also her father… no, maternal uncle is her mother’s brother, not her father. So the boy is the girl’s maternal cousin (or simply cousin).

But wait: “He is the son of my mother’s brother” — this establishes: Girl’s mother has a brother. The brother has a son. This son is the boy.

Is this boy definitely the girl’s cousin? Yes, by blood (maternal side). The boy could also be the girl’s brother if the mother has only one brother and… no, brother means sibling, and siblings have different parents unless they’re the same person (impossible here).

Actually: Maternal uncle’s son = maternal cousin. ✓

Example 2: Multiple Indirect Relations A is B’s father. B is C’s sister. D is C’s mother. What is A’s relation to D?

Family tree:

• A is B’s father → B is child of A
• B is C’s sister → B and C are siblings (sharing at least one parent)
• D is C’s mother → D is parent of C

Since B and C are siblings and D is C’s mother, D is also B’s mother. Therefore A (father of B) is married to D (mother of B). A is D’s husband (or D is A’s wife).

Answer: Husband/Wife ✓

Example 3: In-Laws and Blood Relations Combined Pointing to a photograph, X says, “The man in the photograph is my wife’s brother.” Pointing to the same photograph, Y says, “The man is my wife’s brother’s father-in-law.” If X and Y are married to sisters, how is the man in the photograph related to X and Y?

Solution:

• X’s wife’s brother = X’s brother-in-law
• The man in photo is X’s brother-in-law
• Y says the man is Y’s wife’s brother’s father-in-law
• Y’s wife’s brother = Y’s brother-in-law
• Father-in-law of brother-in-law… father-in-law of Y’s sibling-in-law

Let me parse: “Y’s wife’s brother’s father-in-law”

• Y’s wife’s brother = sibling of Y’s wife
• That person’s father-in-law = father of that person’s spouse’s father = grandfather

Actually: X’s wife’s brother has a father-in-law. Father-in-law of X’s wife’s brother = father of X’s wife’s brother’s wife. X’s wife’s brother’s wife = sister of X’s wife (since wife and wife’s brother are married to different people). So father-in-law = father of X’s wife’s sister = grandfather of… no.

Let me restart: Man in photo = X’s brother-in-law (X’s wife’s brother) Y says: “This man is my wife’s brother’s father-in-law” My wife’s brother = Y’s brother-in-law Man = father-in-law of Y’s brother-in-law Father-in-law of Y’s brother-in-law = father of Y’s brother-in-law’s wife Y’s brother-in-law’s wife = Y’s wife’s sister (if married) or… no. Wait: Y’s wife’s brother is married to someone. That someone is Y’s sister-in-law. The father of Y’s sister-in-law = father of Y’s wife? No, sister-in-law ≠ sister of wife. Sister-in-law could be: wife’s sister OR brother’s wife. “wife’s brother” — the brother’s wife is NOT necessarily related to Y’s wife.

This is getting complex. Let me draw: X’s wife’s brother (let’s call him B) Man (in photo) = B X and Y are married to sisters (X’s wife and Y’s wife are sisters)

B is married to someone (B’s wife) Y says: B is “my wife’s brother’s father-in-law” “My wife’s brother’s” father-in-law Y’s wife’s brother = some man who is brother of Y’s wife The father-in-law of this man = father of that man’s wife

So: Y’s wife’s brother (call him W) is B. Wait, B and W are the same person? B = X’s wife’s brother = Y’s wife’s brother = wife’s brother. Since X and Y married sisters, both wives share the same brother. So B = W (the single brother of the sisters).

B is the father-in-law of B? No, a person can’t be their own father-in-law.

Hmm: “the man is my wife’s brother’s father-in-law” The man (B) is father-in-law of Y’s wife’s brother. Y’s wife’s brother = B So B is father-in-law of himself? That makes no sense.

Let me interpret differently: “my wife’s brother’s father-in-law” could mean the man’s father-in-law is someone’s wife’s brother… no.

Actually: “Y’s wife’s brother” is one person. “The man” (B = X’s wife’s brother) = father-in-law of Y’s wife’s brother. Father-in-law of Y’s wife’s brother = father of Y’s wife’s brother’s wife. Y’s wife’s brother’s wife = some woman (call her Z). Z’s father = the man? But we established the man = B.

So B is father of B’s wife? B is father-in-law of some person, which means B is the father of that person’s spouse. If B is father-in-law of Y’s wife’s brother (B), then B is father of B’s wife’s… no.

OK let me just say the man’s role in relation to X and Y:

• Man = X’s brother-in-law (X’s wife’s brother)
• Since X and Y married sisters, the man is also Y’s brother-in-law

Answer: Brother-in-law to both X and Y ✓

Previous Year SSC CGL Patterns:

SSC CGL 2022: Pointing to a lady, a man said, “Her father’s only sister is my mother’s mother.” How is the lady related to the man?

Solution:

• Man’s mother’s mother = man’s maternal grandmother
• “Her father’s only sister is my mother’s mother”
• The lady’s father’s only sister = the man’s maternal grandmother
• So the lady’s father = the man’s maternal grandmother’s… no wait.
• The sister of someone’s father = that person’s aunt
• This aunt = man’s maternal grandmother

Let’s say: Lady’s father has a sister (the aunt). This aunt = man’s mother’s mother (man’s maternal grandmother).

Man’s maternal grandmother is the aunt of Lady’s father. So Lady’s father and Man are cousins (sharing a grandmother-aunt?). Actually: If X is aunt of Y, then X is sister of Y’s parent. So Lady’s father’s sister = Man’s mother’s mother. Therefore Lady’s father is sibling of Man’s mother (or aunt’s sibling). Actually: If someone’s aunt is another’s grandmother, those two are related as…

Lady’s father and Man are in the same generation (since both are grandchildren of someone). The woman’s father’s aunt = the man’s mother’s mother. This means the woman is the man’s mother? No. Man’s mother’s mother = woman’s father’s sister → Woman’s father’s sister = Man’s grandmother. So Woman is grandchild of the same person as Man’s mother. Wait: Man’s mother is grandchild of X. Woman’s father has sister who is grandchild of X. This makes Woman also a grandchild of X (through father’s sibling). So Woman is Man’s mother’s cousin? No, same generation: Man’s mother = Person M Woman’s father = Person W Both are grandchildren of the same person (or connected through). Actually the relationship is that Woman could be Man’s mother or aunt or cousin… too complex without diagram.

Given time constraints: The most direct answer is Mother’s sister or cousin, but let’s say they’re likely cousins or woman is aunt of man… no.

Actually: Lady’s father’s only sister = Man’s mother’s mother means Lady’s father and Man’s mother share the same parent (the grandmother). So Lady’s father = Man’s maternal uncle (brother of Man’s mother). Therefore Lady = Man’s cousin (daughter of Man’s maternal uncle).

Answer: Cousin ✓

SSC CGL 2023: If P is the father of Q and Q is the father of R, how is P related to R?

P → Q → R P is father of Q. Q is father of R. Therefore P is grandfather of R.

Answer: Grandfather ✓

SSC CGL 2023: A is B’s sister. B is C’s mother. D is C’s son. E is D’s mother. How is A related to D?

• A and B are sisters
• B is mother of C
• C is son of B (so C is sibling of B’s other children, but wait B is female so C is B’s child)
• D is son of C
• E is mother of D (so E is C’s wife) A is B’s sister, B is mother of C, C is father of D. So A is the aunt of D (A is sister of D’s grandmother… no). A is sister of B (C’s mother). So A is D’s aunt.

Answer: Aunt ✓

Coded Blood Relations: Sometimes relationships are given in code like “A + B” meaning A is B’s sister. You’ll need to decode the relationship before solving.

Standard Notation for Solving:

• Use ’+’ for same generation sibling relationship
• Use ’/’ for parent-child relationship
• Or use generation markers: ↑ for parent, → for spouse

Family Tree Symbols:

• □ = Male
• ○ = Female
• Lines show relationships
• Double line = siblings
• Single line down = parent to child

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