Logical & analytical reasoning

Answer: (d) OFXPMLD

Reversing the alphabet swaps each letter with its mirror, whose position adds up to 27 with its own: L→O, U→F, C→X, K→P, N→M, O→L, W→D, giving OFXPMLD.

1. In the reversed alphabet, the letter at position p becomes the letter at position 27 − p (A ↔ Z, B ↔ Y, …).
2. L (12) → O (15); U (21) → F (6); C (3) → X (24); K (11) → P (16).
3. N (14) → M (13); O (15) → L (12); W (23) → D (4).
4. LUCKNOW → OFXPMLD.
5. Check: the second letter separates the options — U (21) → F (6), which rules out (a) and (b); the last letter W (23) → D (4) rules out (c).

Remember · Opposite letters in the alphabet have positions adding to 27 (A–Z, B–Y, …).

Question and answer: UPSC's official GS Paper II (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (c) I

The series is built in blocks A | AB | ABC | ABCD | …, the nth block having n letters. The first 13 blocks use 91 places, so the 100th place is the 9th letter of the 14th block, which is I.

1. Split the series into blocks: A | AB | ABC | ABCD | ABCDE | … The nth block runs from A to the nth letter and has n letters.
2. Places used by the first n blocks = 1 + 2 + … + n = n(n + 1)/2. For n = 13 this is 13 × 14 ÷ 2 = 91.
3. So the 100th place is the 100 − 91 = 9th letter of the 14th block (A to N).
4. The 9th letter of the alphabet is I.
5. Check: the 14th block ends at place 91 + 14 = 105, so place 100 does fall inside it.

Remember · Growing-block series: find the largest n with n(n + 1)/2 below the position; the remainder names the letter.

Question and answer: UPSC's official GS Paper II (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

UPSC dropped this question from evaluation in its final answer key.

UPSC dropped this item from evaluation. The idea is still worth learning: Q and R are P’s parents and P and U are T’s parents, so T is Q’s granddaughter, while Q’s and R’s genders are never stated.

1. R’s son is P and R is Q’s spouse, so Q and R are P’s parents — the first couple.
2. P’s daughter is T and U is T’s mother, so P (male, being R’s son) and U are T’s parents — the second couple. S is U’s other daughter.
3. The genders of Q and R are never given, so (a), (b) and (c) cannot be decided.
4. T is the daughter of P, who is Q’s son, so T is Q’s granddaughter — as in option (d).

Remember · Blood relations: draw the tree with gender marks; any option that needs an unstated gender cannot be definitely correct.

Question and answer: UPSC's official GS Paper II (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (d) None of the Conclusions follows

“All pens are books” and “No chair is a pen” say nothing definite about chairs and books. Conclusions I and IV are only possibilities, II contradicts Statement–2, and III is impossible, so none follows.

1. Draw the circle ‘pens’ inside ‘books’ (All pens are books) and ‘chairs’ outside ‘pens’ (No chair is a pen).
2. ‘Chairs’ may lie wholly inside ‘books’ (outside the pens), partly inside, or wholly outside — the statements do not decide.
3. So Conclusion–I and Conclusion–IV are possible but not certain; Conclusion–II contradicts Statement–2; Conclusion–III would make every pen a chair, which Statement–2 forbids.
4. None of the conclusions follows.

• ✗ I Possible (chairs may lie inside books, away from the pens) but not certain.
• ✗ II Directly contradicts Statement–2: no chair is a pen.
• ✗ III If all books were chairs, the pens (which are books) would be chairs — impossible under Statement–2.
• ✗ IV Possible (chairs may lie wholly outside books) but not certain.

Remember · Syllogisms: a conclusion follows only if it holds in every possible diagram, not just in one.

Question and answer: UPSC's official GS Paper II (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (c) Both Conclusion–I and Conclusion–III

The doctors who are teachers are, by the chain of ‘all’ statements, also engineers and scientists. So “some engineers are doctors” and “some scientists are doctors” both follow; “all engineers are doctors” does not.

1. Some doctors are teachers, and all teachers are engineers, so those doctors are engineers: some engineers are doctors (III follows).
2. All engineers are scientists, so the same doctors are scientists: some scientists are doctors (I follows).
3. Nothing says every engineer is a doctor, so II does not follow.

• ✓ I The doctor-teachers are engineers and hence scientists, so some scientists are doctors.
• ✗ II Only some engineers (those who are teacher-doctors) are known to be doctors; ‘all’ goes beyond the statements.
• ✓ III The doctors who are teachers are engineers, so some engineers are doctors.

Remember · A ‘some’ link passes down a chain of ‘all’ links: some A are B and all B are C, so some A are C.

Question and answer: UPSC's official GS Paper II (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error