Logical & analytical reasoning

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