Blood Relations in Aptitude Tests: Solve Any Family-Chain Problem

Blood relations questions test whether you can trace a family chain without getting lost in layers of uncles, aunts, and cousins. They show up in every major placement aptitude test because they are short, deterministic, and reliable at separating students who follow a chain step by step from those who guess.

Why Placement Tests Include Blood Relations

The appeal for test designers is simplicity. A blood relations question fits in three lines, has exactly one correct answer, and cannot be solved by intuition or domain knowledge. The only variable is whether the test-taker follows the chain without making an error mid-way.

Logical reasoning sections in TCS NQT, AMCAT, Wipro National Talent Hunt, and Infosys InfyTQ all carry blood relations questions. Companies running higher-difficulty screening, such as those with the kind of reasoning rounds documented in D.E. Shaw interview patterns, include multi-step family-chain puzzles that require the same fundamental technique scaled up.

Relationship Terminology Reference

Getting the terminology right before touching questions removes most errors. The table below covers every term that appears in standard placement tests.

Relation	Meaning
Paternal grandfather	Father’s father
Maternal grandfather	Mother’s father
Paternal grandmother	Father’s mother
Maternal grandmother	Mother’s mother
Paternal uncle	Father’s brother
Maternal uncle	Mother’s brother
Paternal aunt	Father’s sister
Maternal aunt	Mother’s sister
Nephew	Brother’s or sister’s son
Niece	Brother’s or sister’s daughter
Son-in-law	Daughter’s husband
Daughter-in-law	Son’s wife
Brother-in-law	Spouse’s brother, or sister’s husband
Sister-in-law	Spouse’s sister, or brother’s wife

Three pairs that generate the most errors:

• Paternal vs. maternal: “paternal” means the father’s side; “maternal” means the mother’s side. They live on opposite branches. Confusing them flips the entire chain.
• Nephew vs. niece: a nephew is a sibling’s son; a niece is a sibling’s daughter. The words look unrelated but they are paired like brother/sister.
• In-law vs. blood: “in-law” always involves marriage, not blood. If a question provides only blood-relation clues and asks about an in-law term, there is a missing marriage clue somewhere.

Additional reference sources for practice: IndiaBix blood relations covers 200+ graded questions by difficulty. GeeksforGeeks blood relations has concept walkthroughs in the same format used by AMCAT and Wipro tests.

Three Question Types You Will Face

Statement-derive questions

A statement connects two people through other relatives. The question asks for the direct relationship. The statement is usually phrased to obscure the connection (“the only daughter of my mother” = the speaker herself).

Work the chain from the inside out. Identify the innermost relation first, then move outward one step at a time.

Photo-pointing questions

A person points to someone in a photograph and states how that person connects to them. The question asks how the person in the photo relates to the speaker. The photo framing is decoration. Ignore it and treat the statement as a chain to trace, exactly as in statement-derive questions.

Symbol-coded questions

A key defines each arithmetic symbol as a relationship. A chain expression connects multiple people using those symbols. Decode the chain one symbol at a time, left to right, then name the final relationship between the first and last person in the chain.

The Symbol-Coding System

Symbol keys vary between question sets. The pattern is always the same: each symbol encodes a directed relationship (A op B = “A is [relation] of B”), and every chain is decoded left to right.

A common key format:

Symbol	Meaning
A + B	A is the mother of B
A - B	A is the brother of B
A % B	A is the father of B
A x B	A is the sister of B

To decode A - M + N x B:

• Step 1: A - M means A is the brother of M.
• Step 2: M + N means M is the mother of N.
• Step 3: N x B means N is the sister of B. Since N and B share the same mother (M), M is the mother of both.
• Reading the chain: A is the brother of M, and M is the mother of B. Therefore A is the maternal uncle of B.

The left-to-right discipline is non-negotiable. Students who decode from right to left, or who try to read the whole chain at once, make sign-conversion errors at step 3 or 4.

Six Worked Examples

Example 1: Self-referential (basic)

• Question: Pointing to a woman, a man says, “She is the daughter of the only son of my grandfather.” How is the woman related to the man?
• Step 1: Only son of my grandfather = the man’s father.
• Step 2: Daughter of the man’s father = the man’s sister.
• Answer: Sister

Example 2: Photo-pointing (indirect)

• Question: Pointing to a photograph, Arjun says, “This man is the son of the only daughter of the father of my brother.” How is Arjun related to the man?
• Step 1: Father of my brother = Arjun’s father.
• Step 2: Only daughter of Arjun’s father = Arjun’s sister.
• Step 3: Son of Arjun’s sister = Arjun’s nephew.
• Arjun is the uncle of the man in the photograph.
• Answer: Uncle (maternal uncle, since Arjun is the maternal side of the child)

Example 3: Statement-derive with maternal uncle outcome

• Question: Vimal says, “Savi’s mother is the only daughter of my mother.” How is Vimal related to Savi?
• Step 1: Only daughter of Vimal’s mother = Vimal’s sister.
• Step 2: Vimal’s sister is Savi’s mother.
• Step 3: Vimal is the brother of Savi’s mother.
• Answer: Maternal uncle

Example 4: Gender-ambiguous (cannot be determined)

• Question: W is the brother of X. X is the sister of Y. Y is the father of Z. How is Z related to W?
• Step 1: W is male (stated as brother).
• Step 2: X is female (stated as sister), connecting W and Y as siblings.
• Step 3: Y is male (stated as father).
• Step 4: W, X, and Y are siblings. W is Z’s uncle (W is the sibling of Z’s father Y).
• Step 5: Z’s gender is not stated.
• If Z is male, Z is W’s nephew. If Z is female, Z is W’s niece.
• Answer: Cannot be determined (nephew or niece depending on Z’s gender)

Example 5: Symbol-coded chain

Key: A + B = A is the mother of B; A - B = A is the brother of B; A % B = A is the father of B; A x B = A is the sister of B.

• Question: Which expression shows that A is the maternal uncle of B?
• Decode A - M + N x B:
  • A - M: A is the brother of M.
  • M + N: M is the mother of N.
  • N x B: N is the sister of B, so M is also the mother of B.
• A is the brother of M, who is the mother of B.
• Answer: A - M + N x B (A is the maternal uncle of B)

Example 6: Pointing-to-gentleman (complex 3-step)

• Question: Pointing to a gentleman, Satya says, “His only brother is the father of my son’s father.” How is the gentleman related to Satya?
• Step 1: My son’s father = Satya’s husband (call him H).
• Step 2: Father of H = Satya’s father-in-law (call him F).
• Step 3: The gentleman’s only brother is F, so the gentleman is the brother of Satya’s father-in-law.
• The gentleman is H’s uncle, which makes him Satya’s uncle-in-law.
• Answer: Uncle (or more precisely, husband’s uncle)

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Four Common Errors

Paternal vs. maternal mix-up

“Paternal aunt” is the father’s sister. “Maternal aunt” is the mother’s sister. A question about “her paternal grandfather’s daughter” is asking about the father’s side, not the mother’s. Drawing the tree makes the branch visible; tracing mentally makes the confusion invisible until the wrong answer is already circled.

The son-of-son’s-mother loop

“Son’s mother” is simply your own mother (assuming you are the son). Questions phrase it this way deliberately. Write it out in one step: son of son’s mother = son of my mother = brother (or me). Do not carry the circular phrasing forward.

Left-to-right discipline in symbol coding

In a chain A op B op C op D, decode A and B first, then B and C, then C and D. Reading the chain right-to-left or trying to “see” the whole chain at once produces sign-conversion errors. The discipline is mechanical: one link, then the next.

Assigning gender without a clue

If the question does not state a person’s gender, do not infer it from context, phrasing, or name. The answer may genuinely be “cannot be determined.” Selecting nephew over niece (or vice versa) when no gender clue exists is a wrong answer, even if it feels more natural.

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The tree-building method described above is the same structured approach companies expect in the reasoning rounds that follow the aptitude screen. Cadence campus placement tests extend this kind of systematic problem-decomposition into technical domains. Once you clear the aptitude layer, the next skill gap most engineering students face is in applying structured reasoning to AI tools.

TinkerLLM runs guided build projects at ₹499 that practise the same tree-and-chain discipline applied to prompt decomposition and LLM task flow. If you can follow a 4-step blood relations chain without losing track, you already have the underlying skill. TinkerLLM gives it a technical surface to work on.