Blood Relations Reasoning Questions

Blood relations questions give a few family statements and ask how two people are related. The reliable way to solve them is to draw a small family tree: note each person’s gender and generation, turn every statement into a link, then read off the answer. Learn the standard terms and watch for traps like unstated gender.

Blood relations is a staple of reasoning sections in placement and competitive tests. Our guides to Infosys, Accenture and Cognizant all list it among the commonly reported topics, and it pairs naturally with syllogisms and coding-decoding.

What Are Blood Relations Questions?

You’re told how some people in a family are connected, in plain statements (“A is B’s sister”), in a pointing form (“Pointing to a man, Meera says, ‘He is the son of my mother’s only brother’”), or in coded symbols. You then work out a relationship the question never states directly. No outside knowledge is needed beyond standard family terms, and every answer comes from combining the given links.

Standard Relationship Terms

Learn these once and most questions become mechanical.

Relation	Term
Father’s father / mother’s father	Paternal grandfather / maternal grandfather
Father’s mother / mother’s mother	Paternal grandmother / maternal grandmother
Father’s brother	Paternal uncle
Father’s sister	Paternal aunt
Mother’s brother	Maternal uncle
Mother’s sister	Maternal aunt
Uncle’s or aunt’s children	Cousins
Brother’s son / brother’s daughter	Nephew / niece
Sister’s husband, wife’s brother	Brother-in-law
Brother’s wife, husband’s sister	Sister-in-law
Son’s wife / daughter’s husband	Daughter-in-law / son-in-law
Spouse’s mother / father	Mother-in-law / father-in-law

A 5-Step Method

Note the genders you know. A name or a word like “brother”, “wife” or “father” fixes gender. Mark unknown gender with a question mark and never assume it.
Start from the person named in the question (or the speaker, in a pointing question).
Place people by generation. Draw parents above, children below, siblings and spouses on the same level.
Add one statement at a time, joining people with the right link: parent-child, siblings, or married couple.
Read the answer off the tree and check it against gender and generation before you choose an option.

In a tree, a plus sign (+) marks a male, a minus sign (−) marks a female, an equals sign (=) joins a married couple, a horizontal line joins siblings, and a vertical line joins parent and child.

Main Question Types

Direct statements: a chain of “A is B’s brother” style facts.
Pointing questions: “Pointing to a girl, Ravi says…” The speaker is a person in the chain, so start from the speaker.
Coded relations: symbols stand for relations, and you translate them back one at a time.
Family puzzles: several people with clues, where you place everyone before answering.

Solved Examples

1. Direct chain. A is B’s brother. C is A’s mother. D is C’s father. How is D related to B? Answer: maternal grandfather. A and B are siblings, so C is also B’s mother. D is C’s father, which makes D the father of B’s mother, B’s maternal grandfather.

2. Pointing (speaker is a man). Pointing to a girl, Ravi (a man) says, “She is the daughter of my mother’s only son.” How is the girl related to Ravi? Answer: his daughter. Ravi’s mother’s only son is Ravi himself, so the girl is Ravi’s daughter.

3. Pointing (speaker is a woman). Pointing to a man, Meera says, “His mother is the only daughter of my mother.” How is the man related to Meera? Answer: her son. Meera’s mother’s only daughter is Meera herself, so the man’s mother is Meera, and he is her son.

4. Generations and gender. P is the brother of Q. Q is the sister of R. R is the father of S. How is P related to S? Answer: paternal uncle. P, Q and R are siblings. R is S’s father, and P is R’s brother, so P is S’s father’s brother.

5. In-laws. A’s wife is B’s sister. How is A related to B? Answer: brother-in-law. A is the husband of B’s sister, which is a sister’s husband.

6. Coded relations. In a code, A + B means “A is the father of B”, A − B means “A is the sister of B”, and A × B means “A is the wife of B”. What does P + Q − R mean? Answer: P is the father of R. P + Q means P is Q’s father. Q − R means Q is R’s sister, so Q and R are siblings. P is therefore the father of R too.

7. Family puzzle. P and Q are a married couple, and P is a man. R is their daughter. S is R’s husband. T is S’s son, and U is T’s sister. How is P related to U? Answer: maternal grandfather. R is U’s mother, since U and T are the children of R and S. P is R’s father, so P is the father of U’s mother, her maternal grandfather.

Common Mistakes

Assuming gender. “Cousin”, “spouse” and “sibling” don’t tell you gender, and neither does a name that could be either. Only use what the question states.
Mixing paternal and maternal. Check whose side the link runs through: father’s side is paternal, mother’s side is maternal.
Misreading “only”. “My father’s only son” is the speaker if the speaker is a man, but the speaker’s brother if the speaker is a woman.
Skipping the generation check. If your answer puts someone in the wrong generation, re-draw the tree.

Practice Questions

Try each on paper, then check the answer.

1. A is B’s sister. C is B’s mother. D is C’s father. E is D’s mother. How is E related to A? Answer: great-grandmother. C is A’s mother, D is C’s father, and E is D’s mother, so E is A’s mother’s father’s mother.

2. Pointing to a photograph, a man says, “I have no brother or sister, but that man’s father is my father’s son.” Whose photograph is it? Answer: his son’s. With no siblings, “my father’s son” is the speaker himself, so the man in the photograph is the speaker’s son.

3. Pointing to a lady, Arun (a man) says, “She is the wife of the only son of my mother.” How is the lady related to Arun? Answer: his wife. The only son of Arun’s mother is Arun, so the lady is his wife.

4. X is the brother of Y, and Y is the mother of Z. How is X related to Z? Answer: maternal uncle. X is the brother of Z’s mother.

5. A is the mother of B. B is the sister of C. C is the father of D. How is A related to D? Answer: paternal grandmother. C is A’s son, and C is D’s father, so A is D’s father’s mother.

6. In a code, A $ B means “A is the mother of B”, A # B means “A is the brother of B”, and A @ B means “A is the daughter of B”. What does P $ Q # R mean? Answer: P is the mother of R. P is Q’s mother, and Q is R’s brother, so Q and R are siblings and P is R’s mother too.

7. Pointing to a man, a woman says, “He is the son of my mother’s only son.” How is the man related to the woman? Answer: her nephew. Her mother’s only son is her brother, so the man is her brother’s son.

8. A is B’s father’s brother’s son. How is A related to B? Answer: cousin. B’s father’s brother is B’s paternal uncle, and his son is B’s cousin.

Frequently Asked Questions

What are blood relations questions in reasoning?

They give statements about how people in a family are connected and ask how two of them are related. They test whether you can combine links and keep track of gender and generation.

How do I solve blood relation questions quickly?

Draw a small family tree, mark known genders, add one statement at a time, and read off the answer. Memorising the standard relationship terms saves the most time.

What is the difference between paternal and maternal relatives?

Paternal relatives are on the father’s side, such as a father’s brother (paternal uncle). Maternal relatives are on the mother’s side, such as a mother’s brother (maternal uncle).

Who is “my father’s only son”?

If the speaker is a man, it is the speaker himself. If the speaker is a woman, it is her brother.

How do coded blood relation questions work?

Each symbol stands for a relation. Translate the symbols one at a time into statements, then chain them like a normal question to find the final relationship.

Which exams ask blood relation questions?

They appear in the reasoning sections of placement tests and in many bank and SSC exams. Our Infosys, Accenture and Cognizant guides list it among the commonly reported topics.