BPSC 71st CCE Prelims General Studies · Question 3 of 150

Correct — D, Father-in-law. Fix the viewpoint first: Mukesh is the speaker, so every 'my' in the sentence is his. Now build the chain outward, one link at a time. 'My son' is Mukesh's son. 'My son's wife' is the woman his son married — Mukesh's daughter-in-law. 'My son's wife's daughter' is that woman's daughter, a girl one generation further down. The sentence then says Rita is the mother of that girl. But the girl has already been defined as the son's wife's daughter, and the mother of a woman's daughter is that woman herself: the chain folds straight back on itself. Rita is therefore the son's wife — Mukesh's daughter-in-law. The question asks for the relation in the other direction, how Mukesh stands to Rita, and the father of a woman's husband is her father-in-law. Mukesh is Rita's father-in-law, option (d). Two things make this airtight rather than merely probable. First, the fold is definitional and not an assumption: even if that granddaughter were not Mukesh's son's own child, the sentence names her as the son's wife's daughter, so her mother is the son's wife whatever else is true. Second, no fact outside the sentence is needed — no ages, no other marriages, no second child. One sentence, four links, and the last link cancels the third.

• (a)Father — The trap the question is actually built around, and the one that catches good candidates. It comes from compressing 'my son's wife's daughter' into 'my granddaughter' and then reasoning that the mother of your granddaughter is your daughter. That is true only for a grandchild through your daughter. For a grandchild through your son the mother is your daughter-in-law, and the stem says son. Mukesh could be Rita's father only if Rita had been born to him, whereas every link after 'my son' in this sentence passes through a marriage.
• (b)Son-in-law — This is the right kind of relation pointed the wrong way. Mukesh could be Rita's son-in-law only if he had married Rita's daughter, which would put him one generation below her; the chain puts him one generation above. The usual route to this answer is answering the wrong direction — the chain naturally yields 'Rita is the daughter-in-law', and a candidate who has that in mind, cannot find 'daughter-in-law' among the four options, and grabs the only other in-law word on the list ends up here.
• (c)Son — Mukesh could be Rita's son only if Rita were his mother, which would put her a generation above him. The sentence places her a generation below: she is married to his son. This option is worth using as a free structural check rather than as a serious candidate — 'son' and 'son-in-law' both put Mukesh in the younger generation, so both are eliminated the moment you know Rita is the son's wife, before you decide anything about blood or marriage.

Blood-relation items are solved by turning a sentence into a chain of directed links and then reading a two- or three-generation tree. Three habits settle almost all of them. First, fix whose viewpoint the possessives belong to: relations stated in quoted speech belong to the speaker, so 'my son' here is Mukesh's son and not his friend's. Second, know the self-folding phrases, because they are the whole trick in one-line items. 'The mother of X's daughter' is X, when X is female; 'the only daughter of my mother' is the female speaker herself; 'my father's only son' is the male speaker himself. Any chain of the form 'the parent of P's child' collapses back to P, so a phrase that appears three links deep is often one link deep. Third, separate ties by birth from ties by marriage. Son, daughter, brother, sister, father and mother are ties of birth; every 'in-law' is a tie of marriage, and each in-law label has a mirror image, so father-in-law and daughter-in-law describe one marriage viewed from opposite ends. Because the mirror exists, the last step of any blood-relation answer must be to check which end the question asked about. 'How is X related to Y' wants the word that describes X.

Reason to it in four steps. Step one, whose 'my'? Mukesh is speaking, so the chain starts at Mukesh. Step two, walk outward: Mukesh, then his son, then his son's wife — that is his daughter-in-law — then her daughter, a granddaughter. Step three, read what the sentence actually asks: it does not ask about the granddaughter, it says Rita is that granddaughter's mother. Since the granddaughter was defined as the son's wife's daughter, her mother is the son's wife, and Rita is Mukesh's daughter-in-law. Step four, turn the relation around, because the question asks how Mukesh stands to Rita, not how Rita stands to Mukesh: the father of a woman's husband is her father-in-law, so the answer is (d). The single fact that discriminates is whose line the grandchild comes through. A grandchild through your son has your daughter-in-law as her mother; a grandchild through your daughter has your daughter as her mother. The stem specifies 'my son's wife', so the son's line, so the mother can only be the daughter-in-law — which is why option (a) is wrong even though it is the answer a candidate reaches by an entirely reasonable-sounding shortcut. Two free eliminations are available before any of this. Rita is one generation below Mukesh, so 'Son' and 'Son-in-law', both of which place Mukesh below her, are structurally impossible; and every link in the chain after 'my son' runs through a marriage, so no relation of birth — 'Father' — can be the answer. That leaves option (d) alone, and the full derivation only confirms it.

• The chain in full: Mukesh → his son → his son's wife (his daughter-in-law) → her daughter. The sentence then names that girl's mother, which is the son's wife herself, so Rita is the daughter-in-law and Mukesh is her father-in-law.
• The self-folding identity that drives the whole question: 'the mother of X's daughter' is X. Any phrase of the form 'the parent of P's child' collapses back to P, so a three-link chain can be one link long.
• The fold needs no assumption at all. Even if the granddaughter were not the son's biological child, the sentence defines her as the son's wife's daughter, so her mother is the son's wife by construction and the answer is unaffected.
• The generation test decides between the two plausible options: a grandchild through your son has your daughter-in-law as mother, a grandchild through your daughter has your daughter as mother. The stem says 'my son's wife', so it is the son's line.
• Standard notation for the rough sheet: a square for a male, a circle for a female, a horizontal double line for a marriage and a vertical line for a parent-to-child link. This question needs four symbols across three generations, and drawing them costs about ten seconds — less than reading the sentence a second time.

• Compressing 'my son's wife's daughter' into 'my granddaughter', losing the information about which line she comes through, and then answering that her mother is your daughter — the route to option (a)
• Answering in the wrong direction: the chain produces 'Rita is the daughter-in-law', while the question asks what Mukesh is to Rita
• Treating a tie as one of birth when every link past the first passes through a marriage

BPSC keeps its blood-relations item to a single quoted sentence built on a self-folding possessive chain, with four one-word options and no diagram, and the marking scheme makes precision pay: the booklet gives +1 for a correct answer and, under its instruction 9, deducts 1/3 for a wrong one, so a relation stated backwards costs one and a third marks against the mark it should have earned. UPSC's own versions in GS Paper-I before 2010 were long set-pieces instead — a family of six or seven lettered persons with professions, marriages and unstated genders spread over five or six clues, as in 1998 and 2009 — and since 2011 the type has lived in CSAT Paper-II. BPSC rewards clean parsing of one sentence; UPSC rewarded systematic tabulation of many.

• practice — not a real PYQ

  Pointing to a woman, Ramesh said, "She is the only daughter of my grandfather's only son." How is the woman related to Ramesh?

  • (a)Sister
  • (b)Mother
  • (c)Aunt
  • (d)Cousin

  Answer(a) Sister — his grandfather's only son is Ramesh's own father, and that father's only daughter is Ramesh's sister.

• practice — not a real PYQ

  Introducing a man, a woman said, "His wife is the only daughter of my mother." How is the man related to the woman?

  • (a)Brother
  • (b)Father
  • (c)Husband
  • (d)Son

  Answer(c) Husband — the only daughter of her mother is the speaker herself, so the man whose wife she is must be her husband.