Blood Relations

Subject: Mental Ability | Frequency: 2-3 questions per APPSC paper | Time: 45-75 sec/question

Introduction

Blood relation questions test your ability to decode family relationships from indirect statements. APPSC favours the "pointing to a person" type and coded relations. The single most important technique is drawing a family tree for every problem — even 15 seconds of sketching prevents errors.

Core Method

1. List all persons mentioned in the problem
2. Draw a family tree using standard notation:
   • Males: square or M; Females: circle or F
   • Horizontal line: marriage / same generation
   • Vertical line: parent-child
3. Process each statement one at a time — add to tree sequentially
4. Mark gender explicitly — never assume gender from names
5. Trace the path from person A to person B on the tree
6. State the relationship — convert the path into a relationship name

Relationship Reference Chart

Paternal Side

Maternal Side

In-Laws

Other

Worked Examples — Easy

Q1: Pointing to a man, a woman said, "His mother is the only daughter of my mother." How is the woman related to the man?

• "Only daughter of my mother" = the woman herself
• Man's mother = the woman
• Answer: Mother

Q2: A is the father of B. B is the sister of C. D is the brother of A. How is D related to C?

• A is father of B and C (B is sister of C, they share parent A)
• D is A's brother = uncle of B and C
• Answer: Uncle

Q3: If P + Q means P is the father of Q, and P - Q means P is the wife of Q, then what does A + B - C mean?

• A is father of B; B is wife of C
• A is C's father-in-law
• Answer: Father-in-law

Worked Examples — Medium

Q4: Pointing to a photograph, Ram said "She is the daughter of my grandfather's only son." How is the person in the photo related to Ram?

• Grandfather's only son = Ram's father
• Daughter of Ram's father = Ram's sister
• Answer: Sister

Q5: A is B's sister. C is B's mother. D is C's father. E is D's mother. How is A related to D?

• C is B's mother, A is B's sister → C is also A's mother
• D is C's father = A's maternal grandfather
• A is D's granddaughter
• Answer: Granddaughter

Q6: In a family: A and B are married. D is son of F, who is mother of A. C is daughter of A. E is brother of C. How is D related to E?

• F is mother of A; D is son of F → D is A's sibling
• A and B married with children C and E
• D is E's uncle (sibling of E's parent A)
• Answer: Uncle

Worked Examples — Hard

Q7: A, B, C, D, E sit in a family. A is son of C. C is married to D. B is daughter of D. D is mother of A. How is E related to B if E is the father of D?

• D is mother of A and B. C is married to D (C is father).
• E is father of D → E is grandfather of A and B
• Answer: E is B's Maternal Grandfather

Q8: If X $ Y means X is father of Y, X # Y means X is mother of Y, X @ Y means X is brother of Y, X % Y means X is sister of Y, then find the relation of P in: P % Q @ R $ S

• P is sister of Q; Q is brother of R; R is father of S
• P is sister of Q and R → P is S's aunt (father's sister)
• Answer: Paternal Aunt (Bua)

Q9: Six people A, B, C, D, E, F. B is the son of F. A's only daughter E is married to B. D is brother of B. C is the daughter of A. How is D related to C?

• A has daughters E and C. E married B. B and D are brothers, sons of F.
• D is B's brother, B is E's husband, E and C are sisters
• D is C's brother-in-law (through marriage connection)
• Answer: Brother-in-law

Shortcuts & Tricks

Common Mistakes

1. Assuming gender from names — rely on stated gender only
2. Confusing "only" qualifier — "Only son" means exactly one son
3. Missing in-law connections — marriage creates a new set of relationships
4. Not drawing the family tree — trying to solve mentally leads to errors on complex problems
5. Confusing maternal/paternal — "Mother's brother" (Mama) differs from "Father's brother" (Chacha)

Exam Strategy

• APPSC keeps these at easy-to-medium difficulty
• Always draw a quick family tree — even 15 seconds of drawing saves errors
• Master the "only son/daughter" interpretations — these appear in 60%+ of questions
• For coded relations: write the legend first, then decode step by step
• Time: 45-75 seconds; complex family puzzles may take longer
• Negative marking: -0.333 — draw the tree to be certain before answering

Practice Questions

1. Pointing to a boy, a girl said "He is the son of my mother's only child." Who is the boy to the girl? → Son
2. A is brother of B. B is sister of C. D is father of A. How is C related to D? → Daughter/Son (gender of C not stated)
3. If M + N means M is mother of N, M - N means M is sister of N, then A + B - C means? → A is mother of B, B is sister of C, so A is mother of C → Mother
4. "My father's only daughter's husband" — who is this to me (if female)? → Husband
5. X is Y's brother. Y is Z's father. W is X's father. How is W related to Z? → Grandfather

Key Terms / Formulas