Blood Relations

Module 09 — Lesson 0009 · In Depth · 45 min

Blood relations are a web across gender and generation. Never guess gender from a name; place everyone on the correct level; decode descriptive phrases from the end backwards.

1. Foundational Concepts: Gender and Generations

A. Gender Identification — Never Assume

Names like Robin, Kiran, Alex are not gender clues. Only gendered terms (mother, nephew, brother-in-law) tell you gender. In rough work, mark every person immediately:

Meaning Symbol
Male + or Square □
Female − or Circle ○
Married couple Double horizontal =
Siblings Single horizontal −
Parent → child (generation) Vertical |

B. Generational Mapping — Vertical Levels

Keeping levels prevents uncle/nephew confusion:

Level Who
Level 1 (Top) Grandparents — grandfather, grandmother
Level 2 Parents — father, mother, uncle, aunt
Level 3 Self & siblings — brother, sister, cousin, brother-in-law
Level 4 (Bottom) Children — son, daughter, nephew, niece
Generational mapping — 4 levels Grandfather ○/□ Grandmother = married Father Aunt Uncle Self Cousin Son/Niece L1: Grandparents L2: Parents L3: Self/Siblings L4: Children
Four levels prevent generation errors; gender symbols prevent assumption traps.

2. Common Relationship Terminology

Description Standard Relation
Mother's / Father's brother Uncle
Mother's / Father's sister Aunt
Brother's / Sister's son Nephew
Brother's / Sister's daughter Niece
Uncle's / Aunt's child Cousin
Brother of one's spouse Brother-in-law
Sister of one's spouse Sister-in-law

3. The Family Tree Method — Visual Logic

Use symbols consistently: male +/□, female −/○, married =, siblings −, generations |. Draw direct links immediately; indirect descriptions need decoding first.

4. Decoding Descriptive Logic — Work Backwards

For "pointing to" questions, decode from the end of the phrase to the beginning.

The "Only" Constraint — Logical Anchor

Worked: "She is the daughter of my grandfather's only son."
End: grandfather's only son → my father.
Next: daughter of [father] → my sister.
So she is my sister. The word "only" eliminated the uncle/aunt branch.

Indirect decoding: "He is the father of my son's uncle" → son's uncle = my brother → father of my brother = my father.

Decoding from the end backwards Grandfather start at end only son → Father daughter → Sister ← decode She is the daughter of my grandfather's only son = my sister
Always start at the far end of the descriptive phrase and work toward the speaker.

5. Advanced Logic: Coded Blood Relations

Symbols represent relationships (e.g., A @ B means A is mother of B). Break the expression into pairs and build the tree left-to-right or right-to-left.

  1. Legend check: list what each symbol (+, @, $, #) means.
  2. Gender verification: identify target's gender from the expression (e.g., K * T means K is daughter → K female).
  3. Relationship chain: connect pairs — in "P % Q + R", link P−Q, then Q−R, then deduce P to R.
Worked: If A + B means A is brother of B, and B − C means B is sister of C, then A + B − C: B is sister of C → B female, A is brother of B → A male, so A is brother of C as well. Gender propagates through the chain.

6. Systematic Solving Methodology

  1. Identify reference point: who is "I"? Start tree there.
  2. Direct info: "A is brother of B" → draw immediately with gender symbols.
  3. Indirect info: decode descriptions like "father of my son's uncle" → break into parts.
  4. Shared variables: find common person across clues to merge partial trees.
  5. Final review: check direction — "How is A related to B?" vs "B related to A" are opposite.

7. Summary of Variables and Symbols

Symbol / Term Meaning
Paternal / Maternal Father's side / Mother's side
In-law By marriage
Sibling / Spouse Brother/sister; husband/wife
+, −, *, / Coded operators for generational/gender links

Never assume gender from?

Which level are grandparents?

Paternal aunt is?

Male symbol in rough work is?

“She is daughter of my grandfather's only son” → she is my?

Coded: K * T means K is daughter → K must be?

First step in any blood relation puzzle?

“How is A related to B?” vs “B related to A” — they are?

Notes

Foundations :-

Gender ⇒ never from name ; use +/□ male, −/○ female ; = married, − sibling, | generation

Levels ⇒ L1 grandparents, L2 parents/aunts, L3 self/siblings/cousins, L4 children/niece

Paternal ⇒ father's side ; Maternal ⇒ mother's side

Decoding :-

Work from end backwards ; “only” ⇒ eliminates branches (eg grandfather's only son = father)

(eg daughter of [father] = sister)

Coded & Method :-

Legend → gender check → chain pairs (P%Q+Q%R→deduce P-R)

Steps: reference (I) → direct links → decode indirect → merge via shared person → check direction (A→B vs B→A)

Primary source: none pinned yet — drop your preferred video/book resource into RESOURCES.md and it will be linked here. Ask me anything that's unclear.

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