Blood Relations for SSC CHSL — Complete Guide to Family Tree Questions

intermediate 18 min read

Concept

Blood relations questions test your ability to decode kinship — who is whose mother, son, niece, or brother-in-law — from either a narrative chain or a coded symbol string. SSC CHSL typically throws these in two flavors: plain-English chains ("A is the father of B, B is the sister of C…") and coded-operator chains ("A + B means A is the father of B, so what does A + B ÷ C mean?").

Think of every blood-relations question as building a family tree node by node. You are never actually reasoning about blood — you are doing graph traversal. Each statement adds one directed edge between two nodes. Your job is to find the shortest path between the start node and the end node, then name that path as a kinship term.

Here is the analogy that makes this stick: imagine a WhatsApp family group. Each person is a dot. Each relationship is an arrow connecting two dots. Male members are squares, female members are circles. Your job is to draw all the arrows from the clues, then read off the relationship between two specific dots. Once you stop treating these as "family puzzles" and start treating them as "draw-the-arrows problems," your accuracy jumps immediately.

The gender of each person is your most critical data point. Most errors come from assuming gender incorrectly. The word "married" tells you the two people are of opposite genders. The words "son/father/brother/husband/uncle/nephew" fix male gender. "Daughter/mother/sister/wife/aunt/niece" fix female gender. Ambiguous names (A, B, P, Q) get their gender assigned only when a clue forces it.

For SSC CHSL, you will see roughly one to two blood-relations questions per attempt. They are considered easy-to-medium marks — solvable in 60–90 seconds if you diagram quickly, but a trap if you try to hold the chain in your head without writing.


Deep Dive

The Four Question Types You Will See

Type 1 — Narrative chain: "P is the son of Q. Q is married to R. R is the sister of S. How is P related to S?" Draw each statement as an arrow. Traverse the path from P to S and name it.

Type 2 — Coded operators: Symbols (×, +, ÷, @, &) are defined to mean specific relationships. You decode the expression left-to-right and build the chain.

Type 3 — Pointing/picture statement: "Pointing to a photograph, Ravi says, 'She is the daughter of my father's only son.' Who is she to Ravi?" Work from the reference person outward — do not start from the unknown person.

Type 4 — Statement-verification: "Which of the following means A is the nephew of B?" — you check which coded string produces that relationship.


The 5-Step Diagram Method

Step 1 — List all persons. Write each unique letter/name down the left margin.

Step 2 — Assign gender where possible. Mark M or F next to each name. Use role words: son/father/brother/husband = Male; daughter/mother/sister/wife = Female. "Married" = the two are of opposite genders.

Step 3 — Draw the tree. Put parents above children. Use a horizontal bar for marriage. Connect siblings at the same level with a bracket. Do not guess — only draw what the clue explicitly states.

Step 4 — Trace the path. Find the two target nodes. Walk the path between them, noting each step: "go up to parent → go across to sibling → go down to child."

Step 5 — Name the relationship. Convert the path to a kinship term using the Reference Table below.


Reference Table — Path to Kinship

| Path from A to B | Relationship (A is ___ of B) | |---|---| | Up 1 (parent) | Father / Mother | | Up 2 (grandparent) | Grandfather / Grandmother | | Up 1, across (parent's sibling) | Uncle / Aunt | | Across (same parents) | Brother / Sister | | Down 1 (child) | Son / Daughter | | Down 2 (grandchild) | Grandson / Granddaughter | | Across, down 1 (sibling's child) | Nephew / Niece | | Marriage cross | Husband / Wife / In-law |

The "in-law" chain: if you reach someone through a marriage edge rather than a blood edge, that person is an in-law. A mother's sibling is aunt/uncle (blood). A wife's mother is mother-in-law (marriage cross).


Decoding Coded Relations — The Left-to-Right Rule

Given: K = R ÷ M

Decode left to right, one operator at a time:

Now stitch: K is the sister of R. R is the mother of M. Therefore K is the sister of M's mother = maternal aunt of M.

The key discipline: never skip ahead. Read one operator, fix that edge, then read the next operator.


The "Only Son/Daughter" Trap

"Father's only son" = the speaker himself (if male) or the speaker's brother (if female, assuming one brother).

"Mother's husband" = the speaker's own father (in a standard family; SSC CHSL does not test divorced/remarried setups unless explicitly stated).

These disguised self-references are the most common trap in pointing-type questions. When you see "my father's only son," stop and ask: is this person themselves? If the speaker is female, then yes — the only son is the brother. If the speaker is male, the only son is the speaker.


Gender-Conflict Detector

When a clue assigns two conflicting genders to the same person, re-read the clue. Coded-relation questions sometimes rely on you confusing the subject and object of the operator. In A @ B, the subject is A, not B. The operator describes A's role. Keep your arrows directional.


Memory Tricks & Shortcuts

patternBox and Circle — Draw Gender Instantly

As you read each clue, immediately draw a square for male persons and a circle for female persons next to their letter. When a clue assigns a gendered role (son, wife, etc.), the shape is decided — cross out any earlier ambiguous placeholder. This visual lock prevents the single most common error in blood relations: swapping genders mid-chain. Standard approach (holding genders in memory across 6-clue chain): 30% error rate. Box-circle method: near-zero gender errors. Step saved: you never re-read clues to recheck gender.

patternReverse the Statement

Every blood-relation statement is reversible. If "A is the father of B," then "B is the son/daughter of A." When the question asks "how is X related to Y?" and you have found "Y is the uncle of X," simply flip: X is the nephew/niece of Y. This reversal takes 3 seconds and eliminates the need to re-trace the entire chain. Standard re-trace: 20 seconds. Flip method: 3 seconds.

patternGeneration Counting for Grandparent Questions

Assign generation numbers: the oldest known ancestor = Generation 0. Each child level = +1. If A is at Gen 0, A's child is Gen 1, grandchild is Gen 2. When the question asks how two people in the chain are related, subtract their generation numbers. Difference of 2 = grandparent-grandchild. Difference of 0 = siblings or cousins. Difference of 1 = parent-child. This turns a 6-step trace into one subtraction. Works for all plain-narrative chains. Step count: trace method = 5–6 steps; generation subtraction = 1 subtraction + gender check = 2 steps.

eliminationCoded Operator: Fix Direction First

In coded-relation chains, before decoding anything, write out each symbol's direction as "left is ___, right is ___." For example, if A + B means "A is the father of B," then + = "left is father of right." Now read the full expression like a sentence. K + L ÷ M = "K is father of L; L is mother of M" = K is the maternal grandfather of M. You eliminate all re-reading of the definition table because you have pre-loaded the direction. Saves: 2–3 re-checks per question = roughly 25 seconds per coded question.

substitutionThe 'Mother's Husband' Trigger

Whenever you see "mother's husband," "father's wife," or "parent's spouse," substitute immediately with "father" or "mother" (in standard SSC CHSL family setups). This collapses a two-step chain into zero steps. Similarly, "father's only son" → substitute with "self (if male)" or "brother (if female)." These substitution triggers compress 3-step pointing questions into 1-step questions. Example: "my mother's husband's son" = "my brother" — done in 5 seconds vs. 30 seconds of tree-drawing.


Fast-Solving Framework

When you see a blood-relations question, run this decision tree in under 10 seconds:

Is it coded (symbols defined)?

Is it a pointing/picture statement?

Is it a plain narrative chain (3+ clues)?

After building your diagram, ask:

  1. Have I fixed the gender of both target persons?
  2. Is my path continuous — no broken links?
  3. Am I answering "A related to B" or "B related to A"? Flip if needed.

If any answer is "no," re-read only the clue that is ambiguous — do not re-read all clues. Target the gap, fix it, move on.


Solved PYQs

Why this question: This is the cleanest example of a coded-expression chain — exactly what SSC CHSL repeats every year with slight symbol variations.

Previous Year Questionपिछले वर्ष का प्रश्न2024
'P + F' means 'P is the son of F' 'P − F' means 'P is the wife of F' 'P × F' means 'P is the brother of F' 'P ÷ F' means 'P is the mother of F' 'P = F' means 'P is the sister of F'. What does 'K = R ÷ M' mean?
  1. K is the daughter of M
  2. K is the niece of M
  3. K is the aunt (mother's sister) of M
  4. K is the sister of M
Solutionसमाधान
K = R means K is the sister of R; R ÷ M means R is the mother of M. So K is the sister of M's mother, which makes K the maternal aunt (mother's sister) of M.

Solving path:


Why this question: A multi-step plain narrative chain with a disguised grandparent relationship — tests generation-counting.

Previous Year Questionपिछले वर्ष का प्रश्न2023
If H is the daughter of R, R is the father of S, S is the son of T, T is the daughter of N, then how is H related to N?
  1. Daughter's daughter
  2. Niece
  3. Daughter
  4. Daughter-in-law
Solutionसमाधान
H is R's daughter; R is T's son (since S is R's son and T's child, T is R's parent); T is N's daughter. So R is N's grandson and H is N's great-granddaughter — but tracing the female line: T is N's daughter and H is T's son R's daughter, making H N's daughter's son's daughter, i.e., daughter's daughter (granddaughter).

Solving path:


Why this question: Classic "mother's husband" pointing-type — tests the self-reference substitution.

Previous Year Questionपिछले वर्ष का प्रश्न2018
Deepthi said to her friend, "That girl playing with the dog is the younger of the two sisters of the son of my mother's husband." How is the girl playing with the dog related to Deepthi?
  1. Daughter-in-law
  2. Grand daughter
  3. Sister
  4. Wife
Solutionसमाधान
Deepthi's mother's husband is her father, so the son of Deepthi's father is Deepthi's brother. The younger of that brother's two sisters is Deepthi's sister, making the girl Deepthi's sister.

Solving path:


Why this question: Tests in-law relationship — a frequently confused category.

Previous Year Questionपिछले वर्ष का प्रश्न2013
C is the mother of A and B. If D is the husband of B, what is C to D?
  1. Mother-in-law
  2. Mother
  3. Aunt
  4. Sister
Solutionसमाधान
C is the mother of B, and D is B's husband, so C is D's mother-in-law.

Solving path:


Why this question: Multi-person chain requiring you to track in-law paths without confusing blood and marriage edges.

Previous Year Questionपिछले वर्ष का प्रश्न2022
L is the sister of G. G is the son of M. M is married to D. D is the sister of E. E is the son of C. C is married to S. S is the sister of P. How is L related to E?
  1. Daughter
  2. Wife's sister
  3. Sister's daughter
  4. Brother's daughter
Solutionसमाधान
G is M's son, and L is G's sister, so L is also M's daughter. M is married to D, and D is E's sister, meaning M is E's sister-in-law (or D's sister relationship). D is the sister of E, and M married D, so L is the daughter of M who is married to D (E's sister). L is E's sister's daughter, i.e., Sister's daughter.

Solving path:


Why this question: Establishes the relationship between two adults via their shared child — tests husband identification.

Previous Year Questionपिछले वर्ष का प्रश्न2020
X is the mother of A, Y is the sister of B's father, R is the father of B, A and Z are sisters, B is the brother of Z. How is R related to X?
  1. Husband
  2. Father-in-law
  3. Son
  4. Father
Solutionसमाधान
X is the mother of A and Z (sisters). B is the brother of Z, so B is X's son. R is the father of B, meaning R is the father of X's child, so R is X's husband.

Solving path:


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