Blood relations: Reasoning Ability Notes for Maharashtra TET (Teacher Eligibility)

Maharashtra TET – Reasoning Ability

Blood Relations

Blood Relation – A relationship that exists because of a common ancestor.
In TET exams, you will be asked to determine the relationship between two people (e.g., “What is the relation of A to B?” or “Who is the sister of X?”).

1. Simple Explanation

Generation – Count of steps from a common ancestor.
- 1st Generation – Parents / Children.
- 2nd Generation – Grand‑parents / Grand‑children.
- 3rd Generation – Great‑grandparents / Great‑grandchildren, etc.
Degree of relation – How many generations apart a person is from the common ancestor.
- Same Generation – Siblings, Cousins.
- Different Generation – Parent, Grand‑parent, Uncle, Aunt, Niece, Nephew, etc.
Direction – Upwards (towards ancestors) or Downwards (towards descendants).
Side – Same side (through mother or father) or opposite side (through siblings’ children).

2. Key Points & Terminology

Term	Definition	Example
Parent	One step up in a lineage.	Mother, Father
Child	One step down.	Son, Daughter
Sibling	Same parents.	Brother, Sister
Grand‑parent / Grand‑child	Two steps up/down.	Maternal Grandfather, Paternal Granddaughter
Great‑grandparent / Great‑grandchild	Three steps up/down.
Uncle / Aunt	Brother or sister of a parent.
Niece / Nephew	Daughter or son of a sibling.
Cousin	Children of two siblings.
Second Cousin	Children of first cousins.
Sister‑in‑law / Brother‑in‑law	Spouse of a sibling or sibling of a spouse.
Half‑relations	Share only one parent. (Often omitted in TET questions.)
Lineage vs. Branch	Lineage = vertical chain; Branch = lateral connections (sisters, cousins).

Rules to Remember

Parent/Child – Move one step up/down.
Sibling – Same generation, same parents.
Uncle/Aunt – Parent’s brother/sister (one step up, then one step sideways).
Niece/Nephew – Child of a sibling (one step sideways, then down).
Grand‑ – Add one more generation.
Great‑ – Add an additional generation.
Cousin – Both are one generation below their parents (who are siblings).
In‑law – Relationship through marriage.
Same‑Generation Relations – siblings, cousins, and their extended forms.
Opposite‑Side Relation – E.g., “cousin of your mother” = your uncle/aunt.

3. Worked Example

Problem

A is the daughter of B. B is the son of C. C is the brother of D. What is the relation of A to D?

Step‑by‑Step Solution

Identify the chain
- A → B (child)
- B → C (child)
- C → D (sibling)
Move up the chain
- A to B (1 step up)
- B to C (2 steps up)
C to D
- C and D are siblings → D is a brother of C.
Translate back to A’s viewpoint
- A is 2 steps above D’s sibling.
- So A is the grand‑daughter of D.

Answer: A is the grand‑daughter of D.

Another Example (With Diagram)

   G (Grandfather)
      |
   P  +  Q
  / \    / \
  B  C  D   E
 / \      \
A   F      H

Question: What is the relation of H to A?
Solution:
1. A → B (child) → P (parent) → G (grand‑parent).
2. G → Q (sibling) → D (child) → H (child).
3. A is great‑grandson of G; H is great‑grandchild of G on the other side.
4. Since they are on opposite sides but same generation relative to G, they are second cousins.

Answer: Second Cousin.

4. Quick Revision Summary

Parent / Child – 1 step up/down.
Sibling – Same parents.
Grand‑ – Add one generation.
Great‑ – Add another generation.
Uncle / Aunt – Parent’s sibling.
Niece / Nephew – Sibling’s child.
Cousin – Children of two siblings.
Second Cousin – Children of first cousins.
In‑law – Relation formed by marriage.
Same‑Generation – Siblings, cousins; Different‑Generation – Parent, Grand‑parent, etc.
Opposite‑Side – “Cousin of mother” → Uncle/Aunt.

Tip:

Draw a family tree or use a table of generations.
Count steps “up” to the nearest common ancestor, then “down” to the target person.
Remember that each “step” (parent or child) changes the generation count by ±1.

Practice Tip:
Create quick flashcards for each term (e.g., “Aunt” on one side