Blood Relations – Reasoning Ability (Chandigarh Police Constable)
Aim of this topic
Identify the exact blood relationship between two persons from a given set of clues (parents, children, siblings, etc.).
1. Simple Explanation
Blood relations are lineage‑based connections that exist because of common ancestors.
They are direct (parent–child, grandparent–grandchild) or collateral (siblings, cousins, aunts/uncles, nephews/nieces).
When solving a problem, you usually:
- List all given facts in a linear or tree format.
- Label each person with a unique symbol (A, B, C, …).
- Mark relationships using arrows or a family tree.
- Trace the chain from the first person to the second to determine the exact relation.
2. Key Points
| Category | Term | Example | How to read |
|---|---|---|---|
| Direct Lineal | Father / Mother | A is the mother of B | A → B (A is B’s parent) |
| Son / Daughter | C is the daughter of A | C ← A (C is A’s child) | |
| Grandfather / Grandmother | D is the grandfather of E | D → E (D is E’s grandparent) | |
| Grandson / Granddaughter | F is the grandson of B | F ← B (F is B’s grandchild) | |
| Collateral (Same Generation) | Brother / Sister | G is the sister of H | G ↔ H |
| Uncle / Aunt | I is the uncle of J | I → J (I is sibling of J’s parent) | |
| Nephew / Niece | K is the nephew of L | K ← L (K is child of L’s sibling) | |
| Cousins | First Cousin | M and N share a set of grandparents | M ↔ N (same generation, common grandparent) |
| Second Cousin | O and P share great‑grandparents | O ↔ P (two generations removed from common ancestor) |
Rules to Remember
- Lineal relationships move upwards (parent, grandparent) or downwards (child, grandchild) in the tree.
- Collateral relationships stay on the same level (siblings, cousins).
- Degree of Cousinship
- First cousin: children of siblings.
- Second cousin: grandchildren of siblings.
- Third cousin: great‑grandchildren of siblings, etc.
- Uncle/Aunt is the sibling of a parent.
- **N