👨‍👩‍👧‍👦 Blood Relations - Complete Theory

Master family relationships - the logical mapping topic!

🎯 What are Blood Relations?

Blood Relations questions test your ability to:

• Understand family relationships
• Map connections between people
• Decode complex relationship statements

Example:

“A is B’s father” + “B is C’s mother” → Question: How is A related to C? → Answer: Grandfather

📐 Basic Relationships

Generation 0 (Your Generation)

Male Relations:

• Brother
• Husband
• Brother-in-law (sister’s husband OR spouse’s brother)

Female Relations:

• Sister
• Wife
• Sister-in-law (brother’s wife OR spouse’s sister)

Generation +1 (Parents’ Generation)

Male Relations:

• Father
• Uncle (father’s/mother’s brother)
• Father-in-law (spouse’s father)

Female Relations:

• Mother
• Aunt (father’s/mother’s sister)
• Mother-in-law (spouse’s mother)

Generation +2 (Grandparents’ Generation)

Male Relations:

• Grandfather (father’s/mother’s father)

Female Relations:

• Grandmother (father’s/mother’s mother)

Generation -1 (Children’s Generation)

Male Relations:

• Son
• Nephew (brother’s/sister’s son)
• Son-in-law (daughter’s husband)

Female Relations:

• Daughter
• Niece (brother’s/sister’s daughter)
• Daughter-in-law (son’s wife)

Generation -2 (Grandchildren’s Generation)

Male Relations:

• Grandson (son’s/daughter’s son)

Female Relations:

• Granddaughter (son’s/daughter’s daughter)

🌳 Family Tree Method

Why Use Family Trees?

• Visual representation prevents confusion
• Tracks multiple generations easily
• 100% accuracy for complex relations

Symbols to Use:

Male: Use □ (square) or (+) or M Female: Use ○ (circle) or (-) or F Marriage: Use = (connecting married couple) Parent-Child: Use | (vertical line) Siblings: Use — (horizontal line)

Example Family Tree:

    □ = ○        (Grandparents)
    Grandfather = Grandmother
          |
    ┌─────┴─────┐
    □           ○  (Parent generation)
 Father = Mother
          |
    ┌─────┴─────┐
    □           ○  (Your generation)
   You       Sister

💡 Solved Examples

Example 1: Basic Relation

Q: A is B’s father. B is C’s mother. How is A related to C?

Solution:

Step 1: Draw family tree

A (M)
  |
B (F)
  |
C

Step 2: Analyze

A → B: Father (A is male, one generation above B) B → C: Mother (B is female, one generation above C)

A → C: A is 2 generations above C, male → A is C’s Grandfather

Answer: Grandfather

Example 2: Sibling Relation

Q: Pointing to a man, a woman said, “His brother’s father is the only son of my grandfather.” How is the woman related to the man?

Solution:

Step 1: Decode “only son of my grandfather”

My grandfather’s only son = My father

Step 2: Rephrase

“His brother’s father is my father” → “His father is my father” → “He is my brother”

Step 3: Draw tree

Grandfather
     |
  Father (only son)
     |
┌────┴────┐

Woman Man (and his brother)

Answer: Sister

Example 3: Complex Chain

Q: A is B’s sister. C is B’s mother. D is C’s father. E is D’s mother. How is A related to D?

Solution:

Step 1: Draw family tree

E (F)
  |
D (M)
  |
C (F)
  |

┌──┴──┐ A(F) B

Step 2: Analyze A → D

A’s generation: 0 (reference) B’s generation: 0 (same as A, they’re siblings) C’s generation: +1 (B’s mother) D’s generation: +2 (C’s father)

A is 2 generations below D, female

Answer: Granddaughter

Example 4: In-Law Relation

Q: A is B’s mother. C is A’s husband. D is B’s wife. How is C related to D?

Solution:

Step 1: Draw tree

C(M) = A(F)
        |
     B(M) = D(F)

Step 2: Analyze C → D

C is married to A A is mother of B B is married to D

C is B’s father D is B’s wife → C is D’s father-in-law

Answer: Father-in-law

Example 5: Tricky “Only” Keyword

Q: Introducing a man, a woman said, “He is the only son of my mother’s mother.” How is the woman related to the man?

Solution:

Step 1: Decode

“My mother’s mother” = My grandmother “Only son of my grandmother” = My mother’s only brother = My uncle

OR

“Only son of my grandmother” could also be = My father (if mother has no brothers)

Step 2: Most likely interpretation

If “only son of grandmother” and woman is granddaughter: → He is her uncle (mother’s brother)

But question asks how WOMAN relates to MAN: If he is uncle, she is niece

Wait! Let’s re-analyze:

“He is the only son of my mother’s mother”

My mother’s mother = Grandmother Only son = Mother’s brother (uncle)

BUT if grandmother had only ONE son: That son = woman’s mother’s only brother = Uncle

However, if we consider: Grandmother’s only son could be woman’s father! (If woman’s mother is female, she’s daughter not son)

So: Grandmother’s only son = Woman’s father → Woman is his daughter

Answer: Daughter (if he’s her father) OR Niece (if he’s her uncle)

Context matters! Usually: Niece

Example 6: Coded Relations

Q: If A + B means A is father of B, A - B means A is wife of B, A × B means A is brother of B, then what does P + Q - R mean?

Solution:

Step 1: Decode symbols

P + Q: P is father of Q Q - R: Q is wife of R

Step 2: Draw tree

P(M)
  |

Q(F) = R(M)

Step 3: Relation P → R

P is father of Q Q is wife of R → P is father of R’s wife → P is R’s father-in-law

Answer: Father-in-law

⚡ Quick Formulas

Formula 1: Generation Count

Count generations between two people:

• Same generation: Brother, Sister, Cousin
• +1 generation: Father, Mother, Uncle, Aunt
• +2 generation: Grandfather, Grandmother
• -1 generation: Son, Daughter, Nephew, Niece
• -2 generation: Grandson, Granddaughter

Formula 2: In-Law Addition

Spouse’s relative = Same relation + “in-law”

Spouse’s father = Father-in-law Spouse’s brother = Brother-in-law Child’s spouse = Son/Daughter-in-law

Formula 3: Double Relations

Father’s brother = Uncle (paternal) Mother’s brother = Uncle (maternal) Father’s sister = Aunt (paternal) Mother’s sister = Aunt (maternal)

For exam: Usually just “Uncle” or “Aunt” unless specified

Formula 4: Cousin Types

Father’s brother’s/sister’s children = Cousins Mother’s brother’s/sister’s children = Cousins

All are simply called “Cousin” in IBPS exams

🎯 Keywords & Decoding

“Only Son/Daughter”

“Only son of X” = X has JUST ONE son (no other sons, may have daughters) “Only daughter of X” = X has JUST ONE daughter (no other daughters, may have sons) “Only child of X” = X has JUST ONE child (no siblings)

“Son/Daughter” (without “only”)

“Son of X” = One of X’s sons (X may have other children too)

“Mother’s Only Brother”

= Mother has EXACTLY one brother = Your maternal uncle (and only one)

“Brother’s Father”

= Your father (you and your brother share the same father)

“Wife’s Father”

= Father-in-law

📊 Relationship Table

⚠️ Common Mistakes

❌ Mistake 1: Gender Assumption

Wrong: “A is B’s child” → A is son ✗ Right: Could be son OR daughter (gender not specified) ✓

❌ Mistake 2: Marriage = Blood Relation

Wrong: Brother-in-law is a blood relation ✗ Right: In-laws are NOT blood relations (married into family) ✓

❌ Mistake 3: “Only” Keyword Ignored

Wrong: “Only son” = “son” (same meaning) ✗ Right: “Only son” means no other sons exist ✓

❌ Mistake 4: Reverse Relation Error

Wrong: If A is B’s father, then B is A’s father ✗ Right: If A is B’s father, then B is A’s son/daughter ✓

❌ Mistake 5: Complex Chain Confusion

Wrong: Try to solve mentally without drawing ✗ Right: ALWAYS draw family tree for 3+ person chains ✓

🎯 Advanced Patterns

Pattern 1: Pointing Photo

Template:

“Pointing to a photograph, A said…”

Strategy:

1. Identify who is in the photo
2. Decode A’s statement about the photo person
3. Find relation between A and photo person

Example:

Pointing to a photo, Ram said: “He is the son of my father’s only son.”

Decode: My father’s only son = Me (Ram) Son of me = My son

Answer: The photo is of Ram’s son

Pattern 2: Conversation Between Two

Template:

A said to B: “Your mother is…”

Strategy:

1. Note who is speaking (A)
2. Note who is listening (B)
3. Decode the relationship mentioned
4. Connect A and B

Pattern 3: Coded Relationships

Template:

Symbols represent relations:

• = father

• = mother × = brother ÷ = sister

Strategy:

1. Replace each symbol with the relation
2. Draw family tree step by step

📝 Practice Problems

Level 1: Basic

1. A is B’s brother. C is B’s mother. How is A related to C?

2. P is Q’s sister. R is Q’s father. How is P related to R?

3. X is Y’s grandfather. Z is Y’s mother. How is Z related to X?

Level 2: Medium

4. Pointing to a man, Rita said, “His mother is the only daughter of my mother.” How is Rita related to the man?

5. A is B’s father. C is A’s mother. D is C’s father. How is B related to D?

6. If P + Q means P is father of Q, P × Q means P is brother of Q, what is P + Q × R?

Level 3: Hard

7. Introducing a woman, a man said, “Her son’s mother is the only daughter of my mother.” How is the woman related to the man?

8. A is B’s sister. B is married to C. D is father of A. E is mother of C. How is E related to D?

9. Ravi said, “This girl is the wife of the grandson of my mother.” How is Ravi related to the girl?

🎯 Exam Strategy

Time Management:

• Per question: 30-45 seconds
• For 5 blood relation questions: 2.5-3.5 minutes

Quick Approach:

1. Read statement (10 sec)
2. Draw family tree (15 sec) - Don’t skip this!
3. Identify relation (10 sec)
4. Verify (5 sec)

Priority:

• ✅ Direct relations (father, mother, brother) - 25 sec
• ✅ One-step decoded (“only son of my father” = me) - 35 sec
• ⏭️ Complex 4+ person chains - 60 sec (attempt last)

🔗 Related Topics

Uses Concepts From:

• Logical reasoning fundamentals
• Family structures

Related Reasoning Topics:

• Puzzles - Arrangement logic
• Direction Sense - Position mapping

Practice:

• Blood Relations Questions

Master Blood Relations - Draw the tree, don’t guess! 👨‍👩‍👧‍👦