Blood Relations: 48-Hour Exam Mastery Guide

Blood Relations: 48-Hour Exam Mastery Guide

What Is This?

Blood relations questions test your ability to decode family relationships from given statements or diagrams. You’ll be asked to identify how two people are related (e.g., "A is B’s uncle") or to reconstruct a family tree from clues.

Why it appears in exams: - Tests logical reasoning and verbal decoding—skills critical for roles in law, HR, policing, and management. - Appears in banking (IBPS, SBI), SSC, railways, CAT, and campus placements. - Typically 2–5 questions per exam, worth 2–5 marks.

Why It Matters

What the examiner wants: - You to translate words into relationships without confusion. - You to avoid traps (e.g., "sister-in-law" vs. "brother-in-law"). - You to solve in under 30 seconds per question.

Core Concepts

Before solving, own these 5 ideas:

1. Gender matters.
2. Brother = male sibling. Sister = female sibling.
3. Niece = daughter of sibling. Nephew = son of sibling.

4. Aunt/Uncle = sibling of parent (or spouse of sibling of parent).

5. In-laws are not blood relatives.

6. Mother-in-law = spouse’s mother (not your blood relative).

7. Brother-in-law = spouse’s brother or sister’s husband.

8. Generational gaps decide hierarchy.

9. Grandparent = parent of parent.

10. Great-grandparent = parent of grandparent.

11. Spouse relationships are bidirectional.

12. If A is B’s husband, then B is A’s wife.

13. Signal words change meaning.

14. "Only son" = no other brothers.
15. "Only daughter" = no other sisters.
16. "Elder/younger" = birth order matters.

The Rule-Book (How It Works)

1. Primary Rule: The Family Tree Method

• Draw a tree with males (?) and females (?).
• Marriages = horizontal line (?).
• Children = vertical line (?) from marriage line.
• Label generations (top = oldest, bottom = youngest).

Example:

  -(Grandfather)
       ?
  -(Grandmother)
       ?
   ?
? (Father)? (Mother)
       ?
  -(You)

2. Sub-Rules & Exceptions

3. Mnemonic: "GPS" for Relationships

• Gender (male/female)
• Parentage (who is whose child?)
• Spouse (who is married to whom?)

Exam / Job / Audit Weighting

• Frequency: High (appears in 90% of reasoning sections).
• Difficulty Rating: Intermediate (easy if you draw trees; hard if you guess).
• Question Type:
• MCQs (pick the correct relation).
• Puzzle-based (reconstruct a family from clues).
• Coding-decoding (e.g., "If ‘A + B’ means A is B’s mother…").

Must-Know Rules, Formulas, Standards

1. The "Spouse Rule":
2. If A is B’s spouse, then B is A’s spouse.

3. A’s mother-in-law = B’s mother.

4. The "Sibling Rule":

5. If A is B’s brother, then B is A’s sibling (could be brother or sister).

6. A’s sister’s husband = A’s brother-in-law.

7. The "Generation Rule":

8. 1 generation up = parents, uncles, aunts.
9. 1 generation down = children, nieces, nephews.
10. Same generation = siblings, cousins, spouses.

Worked Examples (Step-by-Step)

Example 1 (Easy)

Question: A is B’s father. B is C’s sister. How is A related to C? Options: A) Father B) Uncle C) Grandfather D) Brother

Solution:
1. Draw the tree: A (?) ? B (?) C (?)
2. B is C’s sister-C is B’s sibling.
3. A is B’s father-A is also C’s father. Answer: A) Father

Example 2 (Medium)

Question: P is Q’s mother. Q is R’s sister. R is S’s son. How is S related to P? Options: A) Husband B) Son C) Brother D) Father

Solution:
1. Draw the tree: P (?) ? ? Q (?) R (?) ? S (?)
2. R is S’s son-S is R’s parent.
3. Q is R’s sister-Q and R are siblings.
4. P is Q’s mother-P is also R’s mother.
5. S is R’s parent-S is P’s spouse. Answer: A) Husband

Example 3 (Hard)

Question: A is B’s brother. C is A’s mother. D is C’s father. E is D’s mother. How is B related to E? Options: A) Great-grandson B) Grandson C) Son D) Nephew

Solution:
1. Draw the tree: E (?) ? D (?) ? C (?) ? ? A (?) B (?)
2. A is B’s brother-B is A’s sibling (could be brother or sister).
3. C is A’s mother-C is also B’s mother.
4. D is C’s father-D is B’s grandfather.
5. E is D’s mother-E is B’s great-grandmother.
6. B is E’s great-grandchild-If B is male, he is her great-grandson. Answer: A) Great-grandson

Common Exam Traps & Mistakes

Shortcut Strategies & Exam Hacks

1. The "Gender First" Rule:
2. Always underline gender words (he, she, brother, sister, uncle, aunt).

3. Example: "A is B’s maternal uncle"-A is male, B’s mother’s brother.

4. The "Spouse Anchor" Trick:

5. If a question mentions husband/wife, start with the couple and build the tree outward.

6. Example: "A is B’s husband. C is A’s mother."-B is C’s daughter-in-law.

7. The "Elimination Grid":

8. For MCQs, eliminate impossible options first.

9. Example: If the question asks for a female relation, cross out all male options (brother, father, son).

10. The "Signal Word" List:

11. Only-no other siblings of that gender.
12. Elder/younger-birth order matters.
13. Maternal/paternal-mother’s side vs. father’s side.

Question-Type Taxonomy

Practice Set (MCQs)

Question 1

A is B’s brother. C is A’s mother. D is C’s father. How is D related to B? Options: A) Grandfather B) Father C) Uncle D) Brother

Correct Answer: A) Grandfather Explanation: - A is B’s brother-B is A’s sibling. - C is A’s mother-C is also B’s mother. - D is C’s father-D is B’s grandfather. Why the Distractors Are Tempting: - B) Father-Ignores that D is C’s father, not B’s. - C) Uncle-Confuses grandfather with uncle. - D) Brother-Misreads the generational gap.

Question 2

Pointing to a man, a woman says, "His mother is the only daughter of my mother." How is the woman related to the man? Options: A) Mother B) Sister C) Aunt D) Grandmother

Correct Answer: A) Mother Explanation: - "Only daughter of my mother" = the woman herself. - "His mother is the only daughter of my mother"-His mother is the woman. - Thus, the woman is the man’s mother. Why the Distractors Are Tempting: - B) Sister-Assumes "only daughter" refers to someone else. - C) Aunt-Confuses mother with aunt. - D) Grandmother-Misreads the generational link.

Question 3

If ‘A × B’ means A is B’s father, ‘A + B’ means A is B’s mother, and ‘A – B’ means A is B’s sister, then which of the following means P is Q’s maternal uncle? Options: A) P × R + Q B) P – R + Q C) R + P – Q D) P + R – Q

Correct Answer: B) P – R + Q Explanation: - Maternal uncle = mother’s brother. - P – R-P is R’s sister. - R + Q-R is Q’s mother. - Thus, P is Q’s mother’s sister-P is Q’s maternal uncle. Why the Distractors Are Tempting: - A) P × R + Q-P is R’s father, R is Q’s mother-P is Q’s grandfather. - C) R + P – Q-R is P’s mother, P is Q’s sister-P is Q’s aunt. - D) P + R – Q-P is R’s mother, R is Q’s sister-P is Q’s grandmother.

Question 4

A family consists of a husband, wife, their son, and their daughter. Who is the son’s sister’s father? Options: A) Husband B) Wife C) Son D) Daughter

Correct Answer: A) Husband Explanation: - Son’s sister = daughter. - Daughter’s father = husband. Why the Distractors Are Tempting: - B) Wife-Confuses father with mother. - C) Son-Nonsensical (son can’t be his own sister’s father). - D) Daughter-Irrelevant.

Question 5

P is Q’s brother. R is P’s mother. S is R’s father. T is S’s wife. How is T related to Q? Options: A) Grandmother B) Mother C) Aunt D) Sister

Correct Answer: A) Grandmother Explanation: - P is Q’s brother-Q is P’s sibling. - R is P’s mother-R is also Q’s mother. - S is R’s father-S is Q’s grandfather. - T is S’s wife-T is Q’s grandmother. Why the Distractors Are Tempting: - B) Mother-Confuses grandmother with mother. - C) Aunt-Misreads the generational link. - D) Sister-Irrelevant.

30-Second Cheat Sheet

1. Draw a tree for every question.
2. Gender first—underline he/she/brother/sister.
3. Spouse anchor—start with the married couple.
4. Generations matter—count up/down carefully.
5. "Only" = no other siblings of that gender.
6. In-laws-blood relatives.
7. Signal words:
8. Maternal = mother’s side.
9. Paternal = father’s side.
10. Elder/younger = birth order.

Learning Path

1. Day 1 (0–12 hours):
2. Memorize core concepts (gender, generations, in-laws).
3. Solve 5 easy questions (direct relations).

4. Draw 3 family trees from scratch.

5. Day 1 (12–24 hours):

6. Learn sub-rules (half-siblings, step-relations).
7. Solve 5 medium questions (puzzle-based).

8. Practice coding-decoding (1–2 questions).

9. Day 2 (24–36 hours):

10. Master exam traps (common mistakes).
11. Solve 5 hard questions (multi-step trees).

12. Time yourself (30 sec per question).

13. Day 2 (36–48 hours):

14. Take a mock test (10 questions, 10 minutes).
15. Review wrong answers and redraw trees.
16. Memorize the 30-second cheat sheet.

Related Topics

1. Seating Arrangements – Often combined with blood relations in puzzles.
2. Direction Sense – Uses similar logical decoding.
3. Syllogisms – Tests "if-then" reasoning, like family trees.