Blood Relation Tips and Tricks for Government Exams

Introduction

In Blood Relations problems, a set of statements describes relationships between family members. Using those statements you must determine the relation between two particular persons. Many questions present a hierarchical family structure spanning several generations (commonly up to seven generations: three above, the current generation, and three below). The usual approach is to translate every sentence into a small family diagram or to work out relationships step by step.

Important blood-relation terms and short definitions

Representation through diagram

Types of blood-relation questions

• Based on conversation or dialogue (pointing statements).
• Based on puzzles (multiple relations given; build a tree).
• Symbolically coded relations (special symbols represent relations).

Conversation or dialogue

These questions use a speaker who points to a person and makes a statement such as "His mother is my mother's only daughter." Key points to solve:

• Identify the person being pointed to and the pronoun reference (his/her/this person).
• Resolve phrases like "my mother's only daughter" - this refers to a unique person (either the speaker if female, or the speaker's sister if the speaker is male).
• Decide the gender of the speaker where names/gender cues are given; otherwise use the information in the sentence to infer gender when necessary.

Example 1: Madhu said, pointing to Shreya, "His mother is my mother's only daughter". How Madhu is related to Shreya?
(a) Father
(b) Son
(c) Grandson
(d) Mother
(e) None of these
Ans: (d)
Solution: 
The statement given is:
Madhu said, pointing to Shreya, "His mother is my mother's only daughter."

Breaking the statement down:

• "His mother" refers to Shreya's mother.
• "My mother's only daughter" refers to Madhu's own mother's only daughter, which is Madhu herself (since Madhu is talking).

This means Shreya's mother is Madhu's sister.

Relationship:

• If Shreya's mother is Madhu's sister, then Madhu must be Shreya's aunt.

However, since none of the options directly suggest "aunt," we must conclude that Madhu is Shreya's mother, as she is referring to her own daughter in the statement.

Example 2: Pointing to a man in a photograph, a man said to a woman, "His mother is the only daughter of your father". How is the woman related to the man in the photograph?
(a) Sister
(b) Mother
(c) Wife
(d) Daughter
(e) None of these
Ans: (b)
Solution:

Based on puzzles

These questions give several statements about many people; you must combine them to form a family diagram and answer several sub-questions. Typical steps:

• List each statement and mark direct parent-child links and sibling relations.
• Decide genders where indicated (words like sister, brother, son, daughter show gender).
• Place spouses on the same horizontal level and join children below.
• Use the diagram to answer questions about relationships.

Example 3: Direction: A is the mother of B. B is the sister of C. D is the son of C. E is the brother of D. F is the mother of E. G is the granddaughter of A. H has only two children B and C.

(i) How F related to H?
(a) Son-in-law
(b) Daughter-in-law
(c) Father-in-law
(d) Granddaughter
(e) Cannot be determined
Ans: (b)
Solution:  A is mother of B. B is sister of C so B and C are siblings. H has only two children B and C, so H is the parent of both B and C. Therefore, A is the mother of both B and C (consistent with A being mother of B and B and C being siblings).

C is male (since D is son of C and E is brother of D). F is mother of E, so F is spouse of C (C's wife). Therefore F is daughter-in-law of H.

(ii) How is C related to E?
(a) Father
(b) Son
(c) Mother
(d) Cousin brother
(e) Cannot be determined
Ans: (a)
Solution:  C is parent of D (D is son of C). E is brother of D, so E is also child of C. Therefore C is the father of E.

(iii) Who is the mother of G?
(a) C
(b) B
(c) F
(d) Either B or F
(e) Either C or F
Ans: (d)

• G is the granddaughter of A
• A is mother of B, and B & C are siblings

So G can be:

• Child of B → then mother of G = B
  OR
• Child of C → then mother of G = F

Symbolic coding of relations

Some questions encode relations with symbols such as ∆, $, *, #. First decode the meanings, then read expressions from left to right to establish parent, sibling, or spouse links. Always note which symbol designates parent/child and which designates sibling.

Example 4: Direction: Read the following information carefully and then answer the question given below.
(a) A ∆ B means A is mother of B
(b) A $ B means A is sister of B
(c) A * B means A is father of B
(d) A # B means A is brother of B

(i) Which of the following means L is paternal grandfather of O?
(a) L*R$M#K#O 
(b) R*L∆P#K$O 
(c) L*M∆R*K#O 
(d) L*R#M*K#O 
(e) None of these
Ans: 
Solution: We need a situation where L is the father of O's father, i.e., L is the paternal grandfather of O.

Now check option (d) step by step in simple words:

• L is the father of R
• R is the brother of M → so R and M are siblings
• M is the father of K
• K is the brother of O → so K and O are siblings

Now build the family:

• Since K and O are siblings, they have the same father → M is the father of O
• Since R and M are siblings, they share the same parent
• Since L is the father of R, L is also the father of M

So we get:

• M is the father of O
• L is the father of M

Therefore, L is the father of O's father
Hence , Correct ans: (d) L is the paternal grandfather of O

General tips & tricks for fast solving

• Draw partial trees only: Don't attempt the whole family at once; add nodes as needed.
• Resolve "only" or "only son/daughter": "My mother's only daughter" is either the speaker (if speaker is female) or the speaker's sister (if speaker is male). "Only" indicates uniqueness which helps eliminate ambiguous persons.
• Handle pointing statements carefully: When someone points and says "his/her", the pronoun usually refers to the pointed person; trace the reference before inferring.
• Mark genders explicitly: Whenever a statement mentions brother/sister/son/daughter, mark the gender of that person on the diagram immediately.
• Translate symbolic expressions left to right: Apply each operator in sequence to find the final relation.
• Use elimination: For multiple-choice answers, try to disprove incorrect options quickly by checking one or two defining relations.
• Check for generation shifts: Words like "grand", "great" indicate a shift up or down more than one generation; count generations carefully.
• Practice common patterns: Examples include "X is my father's brother" (X is paternal uncle), "X is my mother's sister's son" (X is maternal cousin/nephew depending on gender), etc.