Blood Relations – Reasoning Ability
(For Andhra Pradesh Police Constable Exam – GATE‑style questions)
1. Simple Explanation
Blood relations (also called consanguineous relations) are relationships that arise from a common ancestor.
They are classified into three main categories:
| Category | Definition | Example |
|---|---|---|
| Ascendants | Ancestors of a person (parents, grandparents, great‑grandparents, …) | Your mother, grandfather |
| Descendants | Offspring of a person (children, grandchildren, great‑grandchildren, …) | Your son, grand‑daughter |
| Collaterals | Relatives who share a common ancestor but are not in a direct line of descent (siblings, cousins, aunts, uncles, etc.) | Your brother, first cousin |
Key rule:
Two people are blood relatives if they share an ancestor, regardless of gender or how many generations separate them.
2. Key Points to Remember
| # | Point | Why it matters |
|---|---|---|
| 1 | Ascendant vs. Descendant | Helps determine “who is older” and direction of the relation. |
| 2 | Collateral Relations | Includes brothers, sisters, nieces, nephews, aunts, uncles, cousins. |
| 3 | Generation Count | The number of “steps” (generations) between two people decides the exact title (1st cousin, 2nd cousin, etc.). |
| 4 | Reciprocal Relations | If A is B’s uncle, B is A’s nephew. |
| 5 | Grand‑ and Great‑ prefixes | Indicate two or more generations. |
| 6 | Same‑Sister/Child Relations | “Sister’s son” is a nephew; “Sister’s daughter” is a niece. |
| 7 | Avoid Gender Bias | Use gender‑neutral terms when not specified. |
| 8 | Linear vs. Lateral | Ascendants/descendants are linear; collaterals are lateral. |
| 9 | Use a Tree Diagram | Visualizing a family tree removes confusion. |
| 10 | Common Ancestor Check | If two people share an ancestor, they are blood relatives. |
3. Worked Example
Question
“Raj’s father is the son of Shankar. Shankar’s mother is the daughter of Yashoda. Who is Raj’s relation to Yashoda?”
Step‑by‑Step Solution
| Step | Explanation | Diagram (simplified) |
|---|---|---|
| 1. Identify the chain of relations |
- Raj’s father → father of Raj.
- Shankar is the son of Raj’s father. |
Raj ← father ← Shankar| | 2. Connect Shankar to Yashoda | - Shankar’s mother is the daughter of Yashoda → Yashoda is grand‑mother of Shankar. |
Yashoda → daughter → Shankar| | 3. Combine the two chains | - Raj → father → Shankar → (through Shankar’s mother) → Yashoda. |
Raj → father → Shankar → mother → Yashoda| | 4. Count generations from Raj to Yashoda | - Raj → father (1) → Shankar (2) → mother (3) → Yashoda (4).
- So Yashoda is great‑grand‑mother of Raj. |
Raj → great‑grand‑mother| | Answer | Yashoda is Raj’s great‑grand‑mother. |
Quick check:
Great‑grand‑mother = 3 generations above you.
(Grand‑mother + 1 generation = great‑grand‑mother)
4. Quick Revision Summary
- Ascendant – parent, grandparent, great‑grandparent, …
- Descendant – child, grandchild, great‑grandchild, …
- Collateral – sibling, nephew/niece, aunt/uncle, cousin.
- Grand‑ prefix = 2 generations; Great‑ = 3 or more.
- Same‑ prefix (e.g., same‑sister) indicates a sibling.
- Reciprocal: uncle ↔ nephew, aunt ↔ niece.
- Tree diagram: Draw a quick sketch; label each relation.
- Check for common ancestor: If two people share an ancestor → blood relatives.
Quick Practice Question
“If Meera is the daughter of Arjun, and Arjun is the son of Rahul, who is Rahul to Meera?”
Answer: Rahul is the grand‑father of Meera.
Feel free to sketch the family tree for each problem – it’s the fastest way to avoid mis‑reading the relations. Good luck with your preparation!