Logical & analytical reasoning

Answer: (d) Neither 1 nor 2

'Good for health' says a morning walk helps. It does not say that every healthy person walks in the morning, nor that good health is impossible without it — so neither conclusion follows.

1. The statement gives a benefit: a morning walk improves health.
2. Conclusion 1 reverses it (healthy → morning walker); a benefit does not make the habit universal among healthy people.
3. Conclusion 2 upgrades 'good for' to 'essential'; there may be other ways to stay healthy.

• ✗ 1. It reverses the statement; healthy people may stay fit in other ways.
• ✗ 2. 'Good for' is not 'essential for'; the statement does not rule out other routes to good health.

Remember · 'Good for' never means 'essential for', and 'A helps B' never means 'all B do A'.

Question and answer: UPSC's official GS Paper II (2017, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (d) 1 is false.

'Some colours are not pleasant' is the exact contradictory of 'All colours are pleasant', so if statement 4 is true, statement 1 must be false. Statements 2 and 3 could go either way.

1. Statement 4 (some colours are not pleasant) and statement 1 (all colours are pleasant) are contradictories: exactly one of them is true.
2. 4 is true, so 1 is false — definitely.
3. Statement 2 may or may not hold, because the remaining colours may or may not be pleasant; so 2 and 3 are both undetermined.
4. Only (d) is certain.

• ✗ (a) 1 is false, so '1 and 2 are true' cannot hold.
• ✗ (b) 4 does not rule out some colours being pleasant, so 3 is not certain.
• ✗ (c) 2 may still be true — some colours can be pleasant while others are not.
• ✓ (d) 'Some … are not' is the contradictory of 'All … are'; when one is true, the other is false.

Remember · Contradictory pairs: All vs Some-not, and No vs Some. If one of a pair is true, the other is false; other pairs stay undetermined.

Question and answer: UPSC's official GS Paper II (2017, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (b) A is the husband of D.

A, E and B are sons, so they are the three males, and C, D and F are the three females. D's son must be B, because A and E are F's sons; so D is B's mother and A is B's father. With only one married couple, A is D's husband.

1. A and E are sons of F, and B is the son of A — so A, B and E are males. Equal numbers means C, D and F are the three females.
2. D is the mother of a boy and a girl. Her boy cannot be A or E, whose mother is F, so it is B.
3. B's father is A and B's mother is D, so A and D are the only married couple.
4. D's girl is C; F, the mother of A, belongs to the older generation.
5. So A is the husband of D.

• ✗ (a) A and B are sons, so they are males.
• ✓ (b) A is B's father and D is B's mother; with only one married couple, A and D are husband and wife.
• ✗ (c) E is F's son, and F is A's mother, so neither is D's child.
• ✗ (d) F is the mother of A, D's husband, so F is D's mother-in-law, not her mother.

Remember · In family puzzles, fix genders first from 'son', 'mother' and similar words, then use 'only one married couple' to pair the parents.

Question and answer: UPSC's official GS Paper II (2017, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (b) 4

'Colour' is the only word in all three phrases and 5 the only digit in all three codes. 'Chalk' is shared by the first and third phrases, whose codes also share 2. That leaves 4 for 'white' in 254.

1. 'colour' is in all three phrases and 5 is in all three codes, so colour = 5.
2. 'chalk' is in 256 and 254; apart from 5 they share 2, so chalk = 2.
3. 254 = white colour chalk, so white = 4.
4. Check: 256 then gives red = 6, and 589 splits green and flower between 8 and 9.

Remember · In word-to-digit codes, match the word common to two phrases with the digit common to their codes, and eliminate step by step.

Question and answer: UPSC's official GS Paper II (2017, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (d) Oranges

Oranges are the only fruit eaten by both B and C, who fell sick, and neither A nor D, who stayed well, ate oranges. Every other fruit was eaten by at least one person who did not fall sick.

1. Sick: B (grapes, oranges) and C (oranges, pineapple, apple). The only fruit common to both is oranges.
2. Well: A (grapes, pineapple) and D (grapes, apple, pineapple) — neither ate oranges.
3. Check: grapes, pineapple and apple were all eaten by someone who stayed well, so they cannot be the cause.

Remember · To find a common cause, take what all affected cases share and strike out anything the unaffected cases also had.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (d) The rate of population growth is increasing due to faster decline in death rate than in birth rate

The rate of population growth is the birth rate minus the death rate. If growth is rising while both rates fall, the death rate must be falling faster — statements 1 and 2 together give (d). Migration within a country does not change its population.

1. Rate of population growth = birth rate − death rate.
2. Statement 1: growth is rising, so the gap between the two rates is widening.
3. Statement 2: both rates are falling, the death rate faster — this widens the gap.
4. Statement 3 would narrow the gap, so it cannot explain rising growth; statement 4 moves people within the country and adds nobody.
5. So growth is rising because the death rate is falling faster than the birth rate.

• ✗ (a) Rural-urban migration shifts people inside the country; it does not change the national growth rate.
• ✗ (b) 'Death rate only' ignores the falling birth rate; growth rises because the death rate falls faster than the birth rate.
• ✗ (c) The birth rate is declining, not increasing.
• ✓ (d) With the death rate falling faster, the birth-minus-death gap widens and growth rises.

Remember · Growth rate = birth rate − death rate; internal migration moves people around but never changes a country's total.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (d) We do not go either for picnic or for trekking

The claim promises that at least one of the two outings will happen. It is proved false only if neither happens — we go neither for a picnic nor for trekking.

1. 'Either a picnic or trekking' is true if at least one of the two happens.
2. (a) and (c) each have one of them happening — the claim holds.
3. (b) says nothing about what we do.
4. Only (d), neither of them happening, makes the claim false.

• ✗ (a) A picnic alone satisfies the 'either … or' claim.
• ✗ (b) Irrelevant: what health authorities encourage says nothing about what we actually do.
• ✗ (c) Trekking alone also satisfies the claim.
• ✓ (d) If neither outing happens, 'either a picnic or trekking' is false.

Remember · 'Either A or B' is falsified only by 'neither A nor B'.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (d) nothing can be said about the gender composition of the party

No man knew music, but only 'many' — not all — of the women did. So six non-musicians could be all men, all non-musical women, or a mix; the fact rules out none of these.

1. Non-musicians: all 30 men and those women who do not know music ('many', not all, women know music).
2. Six non-musicians could be drawn entirely from men, entirely from non-musical women, or from both.
3. Each of (a), (b) and (c) is possible but none is certain, so nothing definite can be said.

• ✗ (a) Women who did not know music could also have been drawn.
• ✗ (b) Men, none of whom knew music, could equally have been drawn.
• ✗ (c) Possible, but not certain — the six could all be men.
• ✓ (d) The non-musicians include all 30 men and some women, so any gender mix fits.

Remember · 'Many' is not 'all'. When a group could be drawn from several sub-groups, no definite conclusion about its make-up follows.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (d) A is older than C

Statement 1 gives A ≥ B and statement 3 gives B > C, so A is certainly older than C. Each other option rests on an 'either … or' that may go the other way, or on a comparison the statements never make.

1. Statement 1: A ≥ B. Statement 2: D ≥ C. Statement 3: B > C.
2. Chain: A ≥ B > C, so A > C.
3. Check the rest: A may equal B; D may equal C; B and D are never compared.

• ✗ (a) A and B may be of the same age.
• ✗ (b) Nothing compares B with D.
• ✗ (c) C and D may be of the same age.
• ✓ (d) A ≥ B and B > C give A > C.

Remember · Write 'either the same age or older' as ≥, then chain the signs; one strict > in the chain makes the result strict.

Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error