Blood Relations – Reasoning Ability
For the Manipur Police Sub‑Inspector (SI) Examination
1. Simple Explanation
A blood relation is a biological connection between two people that arises from common ancestry.
It does not include marital or adopted links.
Typical blood‑relation categories:
| Category | Typical example | How it’s determined |
|---|---|---|
| Direct Line | Parent ↔ Child | Same lineage, one generation apart |
| Collateral | Siblings, Cousins, Nephews/Uncles | Share a common ancestor but are not on the same line |
| Extended | Great‑grandparents, Great‑grandchildren, 1st/2nd cousins, etc. | Count the number of generations between the two people |
In reasoning questions you usually have to:
- Identify the type of relationship (parent, child, sibling, etc.).
- Count the generations that separate the two persons.
- Use the standard nomenclature (e.g., cousin, uncle, nephew).
2. Key Points (Quick Reference)
| Term | Definition | Degree (generations apart) | Example |
|---|---|---|---|
| Parent | Biological mother or father | 1 | A is parent of B |
| Child | Biological son or daughter | 1 | B is child of A |
| Sibling | Share both parents | 0 | A and B are siblings |
| Grandparent / Grandchild | 2 generations apart | 2 | A is grandparent of C |
| Uncle / Aunt | Parent’s brother / sister | 2 | A is uncle of C |
| Niece / Nephew | Child of sibling | 2 | A is niece of B |
| First Cousin | Children of siblings | 2 | A and B are first cousins |
| Second Cousin | Children of first cousins | 4 | A and B are second cousins |
| Great‑Grandparent / Great‑Grandchild | 3 generations apart | 3 | A is great‑grandparent of D |
| Second‑Degree Relatives | Any relation that is 2 steps away (e.g., grandparent, uncle, niece, etc.) | 2 | A and B are second‑degree relatives |
| Third‑Degree Relatives | 3 steps away (e.g., great‑grandparent, great‑aunt, etc.) | 3 | A and B are third‑degree relatives |
Rule of thumb:
Number of generations between two persons = degree of separation.
Use the table above to convert that number into the correct relational term.
3. Worked Example
Problem
If X is the son of Y, Y is the son of Z, and Z is the father of W, what is the relationship between X and W?
Step‑by‑Step Solution
| Step | Logic | Result |
|---|---|---|
| 1 | Identify the chain of relations. | X → Y → Z → W |
| 2 | Determine generations between X and W. | X to Y (1), Y to Z (2), Z to W (3) → 3 generations apart |
| 3 | Check if they share a common ancestor. | Yes, Z is the common ancestor. |
| 4 | Since X is 3 generations below Z, X is a grandchild of Z. | |
| 5 | W is a child of Z. | |
| 6 | Find relationship between a grandchild and a child of the same parent. | The child (W) is the uncle (or aunt) of the grandchild (X). |
| 7 | Final answer. | W is the uncle of X (or X is the nephew of W). |
Answer – W is the uncle (or aunt) of X.
4. Quick Revision Summary
| Relationship | How to Identify | Generational Gap | Common Terminology | |--------------|-----------------|