Blood Relations Master - Quick Revision

Blood Relations Master - Quick Revision

One-Liners
  1. Mother’s or Father’s son → Brother
  2. Mother’s or Father’s daughter → Sister
  3. Mother’s or Father’s brother → Uncle
  4. Mother’s or Father’s sister → Aunt
  5. Uncle’s or Aunt’s son → Cousin
  6. Uncle’s or Aunt’s daughter → Cousin
  7. Brother’s or Sister’s son → Nephew
  8. Brother’s or Sister’s daughter → Niece
  9. Son’s wife → Daughter-in-law
  10. Daughter’s husband → Son-in-law
  11. Sister’s husband → Brother-in-law
  12. Brother’s wife → Sister-in-law
  13. Grandson’s mother → Daughter-in-law
  14. Granddaughter’s father → Son-in-law
  15. Father of my spouse → Father-in-law
  16. Mother of my spouse → Mother-in-law
  17. Spouse of my sibling → Brother/Sister-in-law
  18. My spouse’s sibling → Brother/Sister-in-law
  19. Only child’s father → Self (if male) / Husband (if female)
  20. Only child’s mother → Self (if female) / Wife (if male)

Formulas/Rules
FormulaUse
P − QP is father of Q (arrow: P → Q)
P + QP is mother of Q (arrow: P → Q)
P × QP is brother of Q (same generation)
P ÷ QP is sister of Q (same generation)
P (m)P is male
P (f)P is female
P — Q (vertical)P is one generation above Q
P = QP & Q are spouses
P * QP is child of Q (reverse arrow)

Memory Tricks
  • “MAIDS” – Mother, Aunt, In-law, Daughter, Sister → always female by default.
  • “FUBU” – Father, Uncle, Brother, Son → default male unless stated.
  • “C-words” – Cousin, Child, Can-be-either; check sex tag.
  • Generation Ladder: Grand → Parent → Self → Child → Grand (never skip 2 steps).
  • In-law Rule: Add “in-law” only when marriage connects two families.

Common Errors
ErrorCorrect
Treating cousin as siblingCousins share grandparents, not parents
Forgetting spouse’s siblings are also in-lawsBrother-in-law = spouse’s brother OR sister’s husband
Assuming uncle’s child = nephewUncle’s child is cousin, not nephew
Confusing maternal & paternalMaternal = mother’s side; Paternal = father’s side
Reading “A is B’s son” as A is fatherReverse: B is parent, A is child

5 Quick MCQs
1. Pointing to a man, a woman says, “His mother is the only daughter of my mother.” How is the woman related to the man?**Answer:** Mother (only daughter of her mother is herself).
2. A is B’s sister. C is B’s mother. D is C’s father. E is D’s mother. How is A related to D?**Answer:** Granddaughter.
3. If X is the brother of the son of Y’s son, how is X related to Y?**Answer:** Grandson.
4. Introducing a boy, a girl said, “He is the son of the daughter of the father of my uncle.” How is the boy related to the girl?**Answer:** Cousin.
5. A man points to a photograph and says, “I have no brother or sister but that man’s father is my father’s son.” Whose photograph is it?**Answer:** His own son’s photograph.