Blood Relations: Concepts, Formulas, and Clear Examples

Blood-relation questions encode family trees in compressed language—‘A is B’s father’s only daughter-in-law’ type chains. Your job is to expand the chain into a small diagram or table and answer who is whose parent, sibling, or cousin.

Campus tests love gender-neutral traps (‘child of,’ ‘only son’) and law vs blood (brother-in-law, step-relations). Draw symbols consistently: male = +, female = −, or use a downward tree; never hold more than one generation in your head without writing.

Notation and diagram habit

• Place the reference person in the center when the question says ‘how is X related to Y?’
• Horizontal line = siblings; vertical = parent–child.
• Mark gender when the text fixes it; if unknown, keep neutral until forced.

Phrase dictionary

• Only daughter / only son → single female/male child in that parent set.
• Sibling of parent → uncle/aunt; child of uncle/aunt → cousin.
• Father’s father → paternal grandfather; mother’s sister → maternal aunt.
• Daughter-in-law → wife of son; sister-in-law → wife of brother or sister of spouse.

Working backward from the question

Start from the named endpoint and unwind one clause at a time. ‘X’s mother’s brother’ = maternal uncle of X.

Example — Chain expansion

Pointing to a man, Rita said, ‘He is the only son of my mother’s mother.’

Rita’s mother’s mother = Rita’s maternal grandmother. That woman’s only son is Rita’s maternal uncle (or father if he is the only son—but ‘only son’ of grandmother is uncle unless father is that son). Typically: the man is Rita’s maternal uncle.

Coded relations

• Replace symbols (@ = mother, # = father) systematically left-to-right or inside-out as the key specifies.
• Build a mini table: Person | Relation to anchor.

Gender inference

If someone is called ‘father,’ they are male. ‘Daughter-in-law’ is female. Some puzzles ask gender of a neutral ‘child’—use the final relation word (nephew → male).

Puzzle sets with multiple speakers

• Align all statements to one anchor generation.
• Contradictions usually mean you misread ‘only’ or ‘eldest.’

Step-by-step method for exam questions

1. Identify the two persons whose relation is asked.
2. Write each descriptive phrase as a small tree fragment.
3. Merge fragments on shared persons (same parent node).
4. Label generations (+1 up, −1 down).
5. Name the relation in standard English (maternal/paternal when needed).
6. Check gender if options differ (nephew/niece).

Formula cheat sheet

Frequently asked questions

Do I need to memorize relation names?

Know common English terms; draw if unsure. Cousin vs second cousin is rare in MCQs.

What if gender is ambiguous?

Use clues from pronouns or relation output (brother-in-law → male).

Fastest method?

Two-person questions: expand from the innermost clause outward in one pass.

Practice on this platform

Use 4 practice sets (10 MCQs, detailed solution after each answer) and 2 timed mocks (20 minutes) on this topic to convert formulas into speed and accuracy.