Blood Relations Notes for Reasoning

Blood relation questions test your ability to understand family relationships from a short statement or a puzzle. They appear in nearly every reasoning section of SSC, banking, railways, defence and state-level exams, and a good student can solve each one in less than 45 seconds. The chapter looks easy but can be confusing, as the same relation can be described in many ways. This note teaches you the vocabulary of relations, the symbol method for drawing family trees, the techniques for pointing questions, coded blood relations and puzzle-based questions, with solved examples, in simple language.

Basic Vocabulary of Relations

The Three Rules for Solving

Rule 1: Break the statement into small steps. Start from the end of the sentence and move backwards, or begin from the person being introduced and trace the relation step by step. Rule 2: Mark gender and generation. Use a plus sign (+) for male, a minus sign (−) for female, and an equal sign (=) or a horizontal line for husband and wife. Write the elder generation at the top and the younger below. Rule 3: Do not assume gender from the name. Names like Sam, Kiran, Jaswant or Ashish can be male or female. If the gender is not given and cannot be fixed from the information, the answer may be "cannot be determined".

Generation Levels

To avoid confusion, mark the generation of each person: grandparents are at +2, parents at +1, brothers, sisters, cousins and spouses at 0, children at −1 and grandchildren at −2. When you add the levels along the chain, the final level gives the generation of the relation. For instance, "mother's father's son" moves +1, +1, −1, which is +1 generation relative to you; and since mother's father's son is the mother's brother, he is your maternal uncle at level +1.

Type 1: Pointing Questions

Example. Pointing to a girl, Anil says, "She is the daughter of my grandfather's only son." How is the girl related to Anil? The only son of Anil's grandfather is Anil's father (or paternal uncle, but if he is the only son, he is Anil's father). The girl is the daughter of Anil's father, so she is Anil's sister.

Example. Introducing a man, a woman said, "He is the only son of my mother's mother." The woman's mother's mother is her maternal grandmother; her only son is the woman's mother's brother. So the man is the woman's maternal uncle.

Type 2: Chain of Relations

Example. A is the father of B. B is the sister of C. C is the mother of D. How is A related to D? Since B and C are sisters, A is also the father of C. C is the mother of D. So A is the father of D's mother, that is, D's maternal grandfather.

Example. How is Rani related to Mohan if Mohan is the son of Rani's husband's only brother? Rani's husband's brother is Mohan's father, so Rani is the wife of Mohan's paternal uncle. Therefore Rani is Mohan's aunt (paternal uncle's wife), and Mohan is her nephew.

Type 3: Coded Blood Relations

Here symbols are used for relations. Suppose A + B means "A is the brother of B", A − B means "A is the sister of B", and A × B means "A is the father of B". For P × Q − R, we read from left to right: P is the father of Q, and Q is the sister of R. So P is the father of R as well. A common practice is to write the relation between consecutive persons, draw the tree and then find the required relation. If the symbol meanings change in the question (for example, A $ B means A is the mother of B), apply them carefully with the given meanings, not the usual ones.

Type 4: Puzzle Based Questions

In these, several clues are given about a family of five to eight persons, and you must find a relation or the position of a person. Draw a family tree and fill the clues one by one. A sample set: A, B, C, D, E and F belong to a family. A is the mother of B. B is the sister of C. D is C's father. E is D's brother. F is E's wife. Here D is the father of B and C, and A is D's wife, since A is the mother of B. So A and D are the parents of B and C; E is the paternal uncle of B and C; and F is their paternal aunt (wife of the uncle). Questions that follow may ask, "How is F related to C?" The answer is paternal aunt (chachi).

Type 5: Relation by "Is the Only..." Clues

Phrases such as "only son", "only daughter" and "only brother" are used to fix a unique person. "My mother's only daughter" is myself or my sister, and "my father's only son" is myself or my brother. If I am male, "my mother's only son" is myself. Use such clues to identify a person without guessing.

Tips for Accuracy

Always read the question twice to find who is "he" and who is "she". Work with the relation asked ("How is A related to B?" is different from "How is B related to A?"). Draw simple lines instead of complicated diagrams. Keep the standard relation chart in memory: father's brother = paternal uncle, mother's brother = maternal uncle, father's sister = paternal aunt, and mother's sister = maternal aunt. Do not mix paternal and maternal sides, and watch out for "in-law" relations, such as husband's or wife's family.

Common Mistakes

Common mistakes include assuming gender from names, mixing up the cousins of the mother's side with the cousins of the father's side, skipping the level of generation, and losing track in long chains. If you are not sure, stop and write the tree; guessing from memory in long questions is risky.

Practice Questions With Answers

Try these without looking at the answers. Question 1: Pointing to a man, Sita said, "His mother is the only daughter of my mother." How is Sita related to the man? The only daughter of Sita's mother is Sita herself, so the man's mother is Sita and she is his mother. Question 2: If P is the brother of Q, Q is the sister of R and R is the father of S, how is P related to S? P and Q and R are siblings, and R is the father of S, so P is the paternal uncle of S. Question 3: A woman says, "This man's wife is my brother's daughter." How is the woman related to the man? The man's wife is the daughter of the woman's brother, so the woman is the aunt of the man's wife. She is the man's wife's paternal aunt (aunt-in-law), and he is her nephew-in-law. Question 4: Ram's mother's mother's only son has a daughter named Tina. What is Tina to Ram? Ram's mother's mother's only son is Ram's maternal uncle, so Tina is Ram's maternal cousin. If you solved these correctly, you understand the method.

How Examiners Make Questions Tricky

Examiners use a few tricks to confuse candidates. They give a long chain with repeated use of "his", "her" and "that person", so that you lose track of the people. They hide gender with neutral names. They use words that sound similar, such as brother-in-law and son-in-law. They give the relation in reverse, such as "A is the son of B's brother", and then ask about B in terms of A. To beat these tricks, always start a diagram, label every person with their initial and their gender, and verify the final answer by reversing the relation. For example, if you find that X is the maternal uncle of Y, then Y should be the nephew or niece of X, which should match the question's request.

Quick Revision

• Break the statement into steps; use + for male, − for female and = for couple.
• Mother's brother = maternal uncle; father's sister = paternal aunt; uncle's or aunt's child = cousin.
• Do not assume gender from a name; note generation levels.

Blood relations is a topic of patience and neat drawing. With regular practice of about ten questions a day, you can bring this chapter to full accuracy within a week.

Related Notes to Read Next

Continue your preparation with these related notes from the same subject:

• Coding-Decoding Notes for Reasoning
• Direction Sense and Seating Arrangement Notes for Reasoning
• Number and Letter Series Notes for Reasoning
• All Reasoning notes

Frequently Asked Questions (FAQ)

What are blood relation questions?

Blood relation questions give information about the relationships among family members and ask you to find how two persons are related.

How do I solve blood relation questions quickly?

Break the statement into small steps, mark male and female with symbols, draw a family tree and trace the relation from one person to the other.

What is the difference between a paternal uncle and a maternal uncle?

A paternal uncle is the brother of one’s father, and a maternal uncle is the brother of one’s mother.

Who is a brother-in-law?

A brother-in-law is the brother of one’s spouse, the husband of one’s sister or the husband of one’s spouse’s sister.

Can I decide gender from the name in these questions?

No. Do not assume gender from names like Sam, Kiran or Ashish unless it is given in the question. The answer may be "cannot be determined".

What does "only son" help us find?

It identifies a unique person. For example, "my grandfather’s only son" is my father, if my grandfather is the paternal grandfather.

How are coded blood relations solved?

Read the meaning of each symbol, write the relation between consecutive persons, draw the family tree and then find the required relation.

What is a cousin?

A cousin is the child of one’s uncle or aunt, from either the paternal or the maternal side.

What is the relation of the sister of one’s father?

She is the paternal aunt of that person.

What does generation level mean?

Generation level shows whether a person is above, equal to or below you in the family tree, such as parents (above), siblings (same) and children (below).

How can I avoid confusion in long chains?

Use symbols and a diagram, write each step on the rough sheet and check gender and generation at every step.

How many blood relation questions come in exams?

Typically 1 to 4 questions appear in reasoning sections of SSC, banking and railways exams, and they are usually quick marks if practised.