Blood relations: Reasoning Ability Notes for Chandigarh Patwari / Lekhpal

Blood Relations – Reasoning Ability

(Chandigarh Patwari / Lekhpal – Study Notes)

1. Simple Explanation

Blood relations (or kinship) are the relationships that exist between people because of common ancestry.
In reasoning problems, you are usually asked to determine the relationship between two persons given a chain of relations such as father, mother, son, daughter, brother, sister, uncle, aunt, cousin, etc.

Key Idea – Treat every person as a node in a family tree and every relation as a labeled edge. By traversing the edges you can deduce any desired relationship.

2. Key Points to Remember

Relation	Common Term	How It’s denoted (in problems)	Example
Direct ancestors	Father, Mother, Grandfather, Grandmother	`father`, `mother`, `grandfather`, `grandmother`	“A is the mother of B”
Direct descendants	Son, Daughter, Grandson, Granddaughter	`son`, `daughter`, `grandson`, `granddaughter`	“C is the grandson of D”
Siblings	Brother, Sister	`brother`, `sister`	“E is the sister of F”
Paternal side	Father’s brother (Paternal Uncle), Father’s sister (Paternal Aunt)	`paternal uncle`, `paternal aunt`	“G is the paternal aunt of H”
Maternal side	Mother’s brother (Maternal Uncle), Mother’s sister (Maternal Aunt)	`maternal uncle`, `maternal aunt`	“I is the maternal uncle of J”
Cousins	First cousins, second cousins, etc.	`first cousin`, `second cousin`	“K is the first cousin of L”
In-laws	Wife’s mother (Mother‑in‑law), Husband’s father (Father‑in‑law)	`mother‑in‑law`, `father‑in‑law`	“M is the father‑in‑law of N”
Spouse	Husband, Wife	`husband`, `wife`	“O is the wife of P”

Rules for Moving Up and Down the Tree

Direction	Symbol	Example
To parent	`parent`	“R is the parent of S”
To child	`child`	“T is the child of U”
To sibling	`sibling`	“V is the sibling of W”
To spouse	`spouse`	“X is the spouse of Y”

Important:

Grand + relation = two steps up or down.
Great‑grand = three steps, great‑great‑grand = four steps.

Common Tricky Pairs

Pair	Relationship	Reason
Aunt/Uncle vs. Aunt/Uncle of spouse	Aunt/Uncle of the spouse is in‑law.	The spouse’s parent is not a blood relation.
Brother of a spouse	Brother‑in‑law	Not a blood relation.
Cousin of a spouse	Cousin‑in‑law	Not a blood relation.

3. Worked Example

Problem Statement

“A is the daughter of B. B is the son of C. C is the sister of D. D is the father of E. What is the relationship between A and E?”

Step‑by‑Step Solution

Identify A’s lineage
- A → daughter of B.
- B → son of C.
- Therefore, A is the granddaughter of C.
Identify E’s lineage
- D → father of E.
- D is the sister of C (since C is sister of D).
- So C is the aunt/uncle of E (C and D share parents).
- Therefore, E is the niece/nephew of C.
Relate A and E via C
- A is the granddaughter of C.
- E is the niece/nephew of C.
- A and E share C as a common ancestor but on different branches.
Determine the specific relationship
- A is the granddaughter of C.
- E is the nephew/niece of C.
- Hence, A and E are first cousins once removed.
- Because A belongs to the next generation after E’s parent (C’s sibling).

Answer: A is the first cousin once removed of E.

4. Quick Revision Summary

Topic	Take‑away
Basic Relations	Know the eight core relations (parent, child, sibling, spouse, uncle/aunt, cousin, grandparent, grandchild).
Directionality	Up = parent, Down = child, Side = sibling, Lateral = in‑law.
Generational Steps	Grand = 2 steps, Great‑grand = 3 steps, etc.
Common Pitfalls	Don’t confuse in‑law with blood relation.
Problem‑Solving Strategy	1) Map the chain, 2) Count steps, 3) Identify common ancestor, 4) Classify cousin degree and removal.
Practice Tip	Draw a quick family tree for each problem.

Quick Mnemonic:
“P‑C‑S‑S‑U‑C‑G‑G”
(Parent, Child, Sibling, Spouse, Uncle/Aunt, Cousin, Grand‑, Great‑grand‑)

Keep practicing with varied chain lengths and mixed relations to build speed and accuracy. Good luck with your reasoning ability preparations!