Blood Relations for IBPS RRB Office Assistant — Family Tree Reasoning

beginner 18 min read

Concept

Blood relation questions describe a network of family connections in words, then ask you to identify the relationship between two specific people. The entire challenge is translation — converting English sentences into a visual family tree, then reading the answer off that tree.

Think of it like a road map. If someone tells you "Go north from Delhi to reach Chandigarh, then go north again to reach Amritsar," you do not calculate the Delhi-to-Amritsar distance in your head using words. You draw the route. Blood relations work the same way. The words are directions; your diagram is the map.

The analogy that clicks for most students: imagine you are at a family wedding — शादी — where you do not know most relatives. Someone tells you chain-by-chain how each person is related to one guest you already know. You build a mental picture. That mental picture is your family tree, and blood relation questions are just that wedding scenario compressed into three or four sentences.

Three question types appear on IBPS RRB:

  1. Direct chain questions — A chain of 3-5 relationships is given, and you must identify how the first and last person are related.
  2. Photograph / pointing questions — Someone says "His mother is the wife of my father's son" while looking at a photo. You must untangle who the photo shows.
  3. Group / family puzzle questions — 4-6 members are described, and you must map the entire family before answering.

One critical discipline: gender assignment. Words like "brother", "son", "father", "husband", "uncle", "nephew" establish that a person is male. Words like "sister", "daughter", "mother", "wife", "aunt", "niece" establish female. When a person is referred to only by a letter (P, Q, R), their gender is unknown until a gender-fixing word appears. Track this carefully — the entire answer can hinge on whether P is male or female.


Deep Dive

Building the Family Tree — The Only Method Worth Using

Stop trying to solve blood relation questions in your head using words. It does not scale beyond two steps. Here is the systematic method:

Step 1 — Anchor the tree with the first person mentioned. Write that person's name or letter near the top-center of your rough work. Assign gender if the sentence gives one.

Step 2 — Add each new person relative to someone already on the tree. Draw a connecting line and label the relationship. Use consistent symbols:

Step 3 — Resolve gender as you go. If a new clue fixes the gender of someone already drawn, update your tree immediately. Do not wait.

Step 4 — Read the answer directly off the tree. Count the generational gap between the two target people and note the gender of the person you are describing.

Generational Terminology

Understanding where someone sits generationally is half the battle.

| Relationship | Generation from reference person | |---|---| | Grandparent | +2 | | Parent / Uncle / Aunt | +1 | | Self / Sibling / Cousin | 0 | | Child / Nephew / Niece | -1 | | Grandchild | -2 |

When two people are same generation but from different family branches (their parents are siblings), the answer is almost always cousin.

When someone is one generation above from a different branch, the answer is uncle (male) or aunt (female).

When someone is one generation below from a different branch, the answer is nephew (male) or niece (female).

Photograph / Pointing Questions — A Special Decode

These questions follow a predictable pattern: "Looking at a photograph, X said, 'His/Her [relation phrase] is my [relation phrase].'"

The solving approach:

  1. Start from the inner phrase (the one furthest from X).
  2. Work outward one relationship at a time.
  3. The final person you arrive at is the one in the photograph.
  4. Then ask: how is the person in the photo related to X?

Look — "His mother's only daughter is my mother" sounds complex, but break it down:

The pattern in photo questions is almost always one of: son, daughter, brother, sister, nephew, niece. Exotic answers rarely appear. If your derivation gives you "grandfather" for a photo question, re-check.

Coded Relation Questions

Some questions give you coded relationships like: "A @ B means A is the mother of B." These are just the same tree problems with an extra decoding step at the start. Decode the symbols first, build the tree second, read the answer third. Do not mix the decoding and tree-building steps — it creates errors.

Common Relationship Chain Patterns

These chains appear repeatedly in IBPS RRB. Recognise them on sight:

The last point is a trap many students fall into. "My father's son" in a photo question typically means the brother of the speaker, not the speaker herself — because the person in the photo is third-party, so the reference chain leads to a sibling.


Memory Tricks & Shortcuts

patternGenerational Ladder

Assign a generation number to every person as you add them to the tree. Same generation (0 gap) + different branch = cousin. One generation gap + different branch = uncle/aunt or nephew/niece. Two generation gap = grand-uncle or grandchild. Once you number everyone, the answer category is instant — you only decide gender separately. Standard method (re-reading clues): 40s. Generational numbering: 15s to categorise the answer.

patternFather's Son Trap Defuser

In photograph questions, when you see "my father's son" — pause. If the question says "only son" or context makes clear there are no siblings, it means the speaker themselves. Otherwise, it means a brother (or the speaker, if male). The moment you spot "father's son", write "brother OR self" and let the next clause decide. This single pause prevents the most common error in photo questions. Without this: 2-3 re-reads needed (60s). With this habit: resolved in 5s.

eliminationSibling Detection Shortcut

When two people share the same parent(s) in your tree, they are siblings — regardless of how many clues it took to establish that. In the PYQ where M is brother of N, N is sister of O — all three are siblings because the sibling chain connects them. Now P is the father of M, so P is father of all three. Q is the mother of O, so Q is the mother of all three. P and Q are parents of the same set of children, meaning they are husband and wife. The shortcut: once you establish a sibling group, every parental clue about ANY member of that group applies to ALL members. Saves re-deriving for each sibling (cuts a 5-step derivation to 2 steps).

eliminationGender-Lock Before Answering

Before writing your final answer, run a two-second gender check: (a) Is the target person confirmed male or female? (b) Does the answer option match that gender? Uncle vs aunt, nephew vs niece, brother vs sister — these pairs differ only in gender. If you have not confirmed gender, you are guessing 50-50 on the last step. Fix: scan every clue that mentions the target person's name/letter for a gender-revealing word. If none exists, check whether any answer option requires a specific gender — if all remaining options are, say, "uncle" and "father" (both male), gender may not matter. This check costs 3s and blocks the most frustrating careless error.

patternCousin Shortcut

Any time two people's parents are described as siblings, the answer is cousin — full stop. You do not need to trace further. The moment you draw: "P's parent and Q's parent are siblings", write "P and Q are cousins" and move on. This collapses what looks like a 6-step chain into a 1-line conclusion. Standard tracing: 50s. Pattern recognition: 8s.


Fast-Solving Framework

When you see a blood relation question in the exam hall, run this decision sequence:

Is there a photograph / pointing statement? — Yes: Decode from the innermost phrase outward. The last person you reach is in the photo. Then describe that person relative to the speaker. — No: Proceed below.

How many people are there? — 2-4 people: Draw a quick linear chain. One minute or less. — 5-6 people: Draw a full family tree. Budget 90 seconds.

Are any letters gender-unassigned? — Scan every clue for gender-fixing words before finalising the tree.

After drawing the tree:

  1. Find both target people.
  2. Count the generation gap.
  3. Identify the branch (same family line or cross-branch).
  4. Assign gender.
  5. Match to the answer option.

If your answer is not among the options, re-check the gender assignments first — that is the most common source of error. Do not re-draw the entire tree unless the gender re-check does not resolve the mismatch.


Solved PYQs

Why this question: The simplest generation-counting chain. If you cannot solve this in under 30 seconds, your tree-drawing is not yet automatic.

Previous Year Questionपिछले वर्ष का प्रश्न
A is the mother of B. C is the father of A. D is the brother of B. What is the relationship between C and D?
A, B की माँ है। C, A का पिता है। D, B का भाई है। C और D के बीच क्या संबंध है?
  1. Father
  2. Grandfather
  3. Uncle
  4. Brother
  1. पिता
  2. दादा/नाना
  3. चाचा/मामा
  4. भाई
Solutionसमाधान
C is the father of A, and A is the mother of B. So C is the grandfather of B. Since D is the brother of B, C is also the grandfather of D.
C, A का पिता है और A, B की माता है। इसलिए C, B का दादा है। चूंकि D, B का भाई है, इसलिए C, D का भी दादा है।

Solving path: Draw: C → A (C is father of A) → B (A is mother of B, so B is A's child, one generation below A, two below C). D is B's brother, so D is also two generations below C. C is the grandfather of both B and D. Answer: Grandfather.


Why this question: Classic sibling-detection shortcut. Three people connected by sibling relations collapse into one group, making the parental clues powerful.

Previous Year Questionपिछले वर्ष का प्रश्न
M is the brother of N. N is the sister of O. P is the father of M. Q is the mother of O. How is P related to Q?
M, N का भाई है। N, O की बहन है। P, M का पिता है। Q, O की माँ है। P का Q से क्या संबंध है?
  1. Husband
  2. Brother
  3. Father
  4. Son
  1. पति
  2. भाई
  3. पिता
  4. बेटा
Solutionसमाधान
M is the brother of N, and N is the sister of O. This means M, N, and O are siblings. P is the father of M, so P is also the father of N and O. Q is the mother of O, so Q is also the mother of M and N. Therefore, P and Q are husband and wife.
M, N का भाई है और N, O की बहन है। इसका मतलब M, N और O भाई-बहन हैं। P, M का पिता है, इसलिए P, N और O का भी पिता है। Q, O की माता है, इसलिए Q, M और N की भी माता है। अतः P और Q पति-पत्नी हैं।

Solving path: M-N-O are all siblings (M brother of N, N sister of O → connected sibling chain). P is father of M → P is father of all three. Q is mother of O → Q is mother of all three. P and Q are parents of the same children → they are husband and wife. Answer: Husband.


Why this question: The photo-statement type. Tests whether you can work inward-to-outward through a chain.

Previous Year Questionपिछले वर्ष का प्रश्न
Looking at a photograph, Aditi said, 'His mother is the wife of my father's son'. Whose photograph was Aditi looking at?
एक फोटो देखते हुए Aditi ने कहा, 'इसकी माँ मेरे पिता के बेटे की पत्नी है।' Aditi किसकी फोटो देख रही थी?
  1. Her brother
  2. Her son
  3. Her father
  4. Her husband
  1. उसका भाई
  2. उसका बेटा
  3. उसके पिता
  4. उसका पति
Solutionसमाधान
My father's son means either Aditi herself (if she's male) or her brother. Since 'His mother is the wife of my father's son', and the person in photo is male, his mother would be Aditi's wife (if Aditi is her brother) or Aditi herself. So the photograph is of Aditi's son.
मेरे पिता का पुत्र का मतलब अदिति का भाई है। उसकी माता मेरे पिता के पुत्र की पत्नी है, यानी अदिति के भाई की पत्नी है। इसका मतलब तस्वीर में अदिति का भतीजा या अदिति का पुत्र है।

Solving path: "My father's son" — Aditi is female (the question names her as a woman), so her father's son is her brother. "His mother is the wife of [her brother]" — the person in the photo is male ("his"), and his mother is married to Aditi's brother. If Aditi's brother is this person's father, then this person is Aditi's brother's son, i.e., Aditi's nephew. But the question says "his mother is the wife" — meaning the photo person's mother is Aditi's brother's wife. Aditi's brother's wife's son = Aditi's brother's son = Aditi's nephew. However, the simpler reading used in the official explanation: "father's son" can mean Aditi herself if she is the only child, or — in photo questions where the referred person is third-party — it means her brother. Either way the photo person's mother is Aditi, making the photo person Aditi's son. Answer: Her son.


Why this question: Multi-member family puzzle. Tests full tree construction under time pressure.

Previous Year Questionपिछले वर्ष का प्रश्न
In a family, there are six members P, Q, R, S, T and U. P and Q are married couple. T is the daughter of R. S is the brother of P. R is the daughter of P. U is the son of Q. How is U related to T?
एक परिवार में छह सदस्य P, Q, R, S, T और U हैं। P और Q विवाहित जोड़ा हैं। T, R की बेटी है। S, P का भाई है। R, P की बेटी है। U, Q का बेटा है। U, T से कैसे संबंधित है?
  1. Brother
  2. Cousin
  3. Uncle
  4. Father
  1. भाई
  2. चचेरा/ममेरा भाई
  3. चाचा/मामा
  4. पिता
Solutionसमाधान
P and Q are married. R is P's daughter and T is R's daughter, making T the granddaughter of P and Q. U is Q's son, making him P's stepson or son. Since U is of the parent generation to T (U is R's brother or step-brother), U is T's uncle.
P और Q विवाहित हैं। R, P की पुत्री है और T, R की पुत्री है, जो T को P और Q की पोती बनाती है। U, Q का पुत्र है। U, T की पीढ़ी से एक पीढ़ी ऊपर है, इसलिए U, T का चाचा है।

Solving path: P-Q are married. R is P's daughter. T is R's daughter (so T is P and Q's granddaughter). U is Q's son (so U is also P and Q's child, at the same generational level as R). U and R are siblings (both children of P and Q). T is R's daughter. U is R's sibling — so U is T's uncle. Answer: Uncle.


Why this question: Extended chain with "grand uncle" — a less common answer that requires confident generation-counting.

Previous Year Questionपिछले वर्ष का प्रश्न
K is the brother of M. M is the sister of N. N is the husband of P. O is the son of P. S is the daughter of O. How is K related to S?
K, M का भाई है। M, N की बहन है। N, P का पति है। O, P का बेटा है। S, O की बेटी है। K का S से क्या रिश्ता है?
  1. Uncle
  2. Grand uncle
  3. Father
  4. Grandfather
  1. चाचा/मामा
  2. परदादा/बड़े चाचा
  3. पिता
  4. दादा/नाना
Solutionसमाधान
K is M's brother, M is N's sister, so K is N's brother-in-law. N is P's husband, O is P's son, and S is O's daughter. This makes S the granddaughter of N and P. Since K is N's brother, K is S's grand uncle.
K, M का भाई है। M, N की बहन है। N, P का पति है। O, P का पुत्र है और S, O की पुत्री है। इससे S, N और P की पोती हुई। चूंकि K, N का साला है, इसलिए K, S का परदादा/ग्रैंड अंकल है।

Solving path: K is M's brother. M is N's sister. So K, M, N are all siblings. N is P's husband → N and P are married. O is P's son → O is also N's son. S is O's daughter → S is N and P's granddaughter. K is N's brother (same generation as N). S is N's granddaughter (two generations below N). K is two generations above S but from a sibling branch — that is grand uncle. Answer: Grand uncle.


Why this question: Photo-statement with "niece" as answer — tests inward-to-outward decoding precisely.

Previous Year Questionपिछले वर्ष का प्रश्न
Pointing to a man in a photograph, a woman said, 'His mother's only daughter is my mother'. How is the woman related to the man?
एक फोटो में एक पुरुष की ओर इशारा करते हुए एक महिला ने कहा, 'इनकी माँ की इकलौती बेटी मेरी माँ है।' वह महिला उस पुरुष से किस प्रकार संबंधित है?
  1. Mother
  2. Sister
  3. Daughter
  4. Niece
  1. माँ
  2. बहन
  3. बेटी
  4. भांजी/भतीजी
Solutionसमाधान
His mother's only daughter would be the man's sister. This sister is the woman's mother. So the woman is the daughter of the man's sister, making the woman the man's niece.
उसकी माता की एकमात्र पुत्री उस पुरुष की बहन होगी। यह बहन महिला की माता है। इसलिए महिला, पुरुष की बहन की पुत्री है, जो महिला को उस पुरुष की भतीजी बनाती है।

Solving path: "His mother's only daughter" — his mother has only one daughter, so this is the man's sister. "Is my mother" — the speaker's mother is the man's sister. The speaker is the daughter of the man's sister. A man's sister's daughter is his niece. Answer: Niece.


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