Blood Relations

Blood Relations

Overview

Blood Relations is a consistently tested topic in MPESB Group 1/2/3 reasoning sections. These questions assess your ability to decode family relationships from given statements and construct a family tree mentally or on paper.

Success in blood relations requires two skills: memorizing the standard relationship terminology (who is a maternal uncle versus a paternal uncle) and developing a systematic approach to draw family trees. Most questions are solvable within 30-60 seconds once you master the technique. The difficulty ranges from direct two-person relationships to complex puzzles involving 6-8 family members across three generations.

This topic connects with other reasoning areas like coding-decoding (when relationships are given in coded form) and puzzles (when blood relations are combined with seating arrangements). Mastering it here gives you an advantage across multiple question types.

Key Concepts

• Generation Mapping: Always identify which generation each person belongs to — grandparents (top), parents (middle), children (bottom). This prevents confusion in complex problems.
• Gender Indicators: Words like son, brother, father, uncle, nephew indicate male. Words like daughter, sister, mother, aunt, niece indicate female. Spouse, parent, child, cousin, sibling are gender-neutral.
• The "Only" Keyword: "A is the only son of B" means B has no other sons (but may have daughters). "A is the only child of B" means B has just one child total.
• Paternal vs Maternal Line: Paternal relations come through father's side (paternal uncle = father's brother). Maternal relations come through mother's side (maternal grandmother = mother's mother).
• In-Laws: Father-in-law/Mother-in-law = spouse's parents. Son-in-law = daughter's husband. Daughter-in-law = son's wife. Brother-in-law = spouse's brother OR sister's husband.
• Cousin Rule: Children of your parents' siblings are your cousins. In Hindi/Indian context, questions may use "cousin brother" or "cousin sister" to specify gender.
• Symbol Convention: Use + for male, - for female, = for marriage, | for parent-child, and — for siblings when drawing trees.

Key Facts

Critical Distinctions:

• Brother of father = Uncle (paternal/chacha/tau)
• Sister of father = Aunt (paternal/bua)
• Brother of mother = Uncle (maternal/mama)
• Sister of mother = Aunt (maternal/mausi)

Worked Examples

Example 1: Direct Relationship

Question: Pointing to a photograph, Ramesh said, "She is the daughter of my grandfather's only son." How is the girl in the photograph related to Ramesh?

Solution:

• Step 1: Grandfather's only son = Ramesh's father (since grandfather has only one son)
• Step 2: Daughter of Ramesh's father = Ramesh's sister
• Answer: Sister

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Example 2: Three-Generation Problem

Question: A is the father of B. C is the daughter of A. D is the wife of B. E is the son of B. How is C related to E?

Solution: Draw the tree:

        A (male)
       / \
      B   C (female)
      |
     =D (wife)
      |
      E (son)

• A has two children: B and C
• E is B's son, making A his grandfather
• C is A's daughter, so C is B's sister
• C is therefore E's aunt (father's sister/bua)
• Answer: Paternal Aunt (Bua)

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Example 3: Complex Puzzle

Question: P is Q's brother. R is Q's mother. S is R's father. T is S's mother. How is P related to T?

Solution: Build bottom-up:

• T is S's mother (T = great-great-grandmother level)
• S is R's father (S = great-grandfather)
• R is Q's mother (R = grandmother level to...)
• P is Q's brother (same generation as Q)

Chain: T → S (son) → R (daughter) → Q and P (children)

P is T's great-grandson (T's son's daughter's son).

• Answer: Great-grandson

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Example 4: Coded Blood Relation

Question: If A + B means A is the mother of B, A - B means A is the brother of B, A × B means A is the father of B, then what does P × Q - R + S mean?

Solution: Read left to right:

• P × Q: P is father of Q
• Q - R: Q is brother of R (so Q and R are siblings, P is father of both)
• R + S: R is mother of S

Final relationship: P is Q's father. Q's sibling R is mother of S. Therefore, P is S's maternal grandfather.

• Answer: P is the maternal grandfather of S

Common Mistakes

• Confusing "only son" with "only child" → "Only son of X" means X may have daughters too. Read precisely and don't assume X has just one child.
• Ignoring gender-neutral terms → When question says "child" or "sibling" without specifying gender, don't assume. Look for other clues or consider both possibilities.
• Reversing in-law relationships → "A is the father-in-law of B" means B married A's child. Students often confuse whether A is the parent or B is the parent.
• Forgetting that cousins share grandparents, not parents → Cousin's father is your uncle, not your father. Many students incorrectly place cousins as siblings.
• Not drawing the tree → Attempting to solve complex problems mentally leads to errors. Always sketch even for seemingly simple questions — it takes 10 seconds and prevents silly mistakes.
• Mixing paternal and maternal lines → "Mother's brother's son" is maternal cousin. "Father's sister's son" is paternal cousin. Track which side of the family you're on.

Quick Reference

• Always draw the family tree — use +/- for gender, = for marriage, vertical lines for parent-child.
• "Only" restricts one category — only son ≠ only child.
• In-laws connect through marriage — trace the spouse first, then find the relation.
• Generation counting: Self = 0, Parents = +1, Grandparents = +2, Children = -1.
• When stuck, start from the person whose relationship is most clearly defined.
• Verify your answer by reading the question backward through your tree.