UPSC Prelims 2023 — CSAT Paper II

CSAT Paper II of the 2023 Preliminary examination, held on 28 May 2023. 80 questions · 200 marks · qualifying at 33%. The questions broke down as Comprehension 27, Basic Numeracy 20, Mental Ability 19, Logical Reasoning 7, Data Interpretation 5.

The answer under each question is UPSC's official key. The note beside it is the first line of our explanation; the full reasoning, option by option, is one click away.

  1. Q1

    Which one of the following statements best reflects the most rational, practical and immediate action required to ensure fair and equitable allocation of water to different stakeholders ?

    • (a)A national, pragmatic, legal and policy framework for water allocation should be made.
    • (b)All river systems of the country should be linked and huge aquifers created.
    • (c)Water channels between regions of water surplus and regions of water deficit should be created.
    • (d)To mitigate water crisis, water demand of sectors such as agriculture and industry should be reduced.

    UPSC's answer: (a) — The passage explicitly states that water is a State subject under the Constitution, except for the regulation of inter-State rivers, which necessitates a unified legal and policy framework to manage these exceptions effectively.

  2. Q2

    Which one of the following statements best reflects what is implied by the passage ?

    • (a)Education system must be strengthened in rural areas.
    • (b)Large scale and effective implementation of skill development programme is the need of the hour.
    • (c)For economic development, health and nutrition of only skilled workers needs special attention.
    • (d)For rapid economic growth as envisaged by us, attention should be paid to health and nutrition of the people.

    UPSC's answer: (d) — The passage highlights that anaemia and tuberculosis cause significant lost productivity among working-age Indians, with women and men being 5–15% less productive due to these health issues.

  3. Q3

    Which one of the following statements best reflects the most logical and rational message conveyed by the author of the passage ?

    • (a)Adaptation to climate change and mitigation response are basically the responsibilities of the government.
    • (b)Climate change causes a change in government policies regarding land use patterns in the country.
    • (c)Risk perceptions of farmers are important for motivating them for taking adaptation decisions.
    • (d)Since mitigation is not possible, governments should come up with policies for quick response to climate change.

    UPSC's answer: (c) — The passage states that while perception is a necessary pre-requisite for adaptation, it is not always sufficient on its own.

  4. Q4

    Raj has ten pairs of red, nine pairs of white and eight pairs of black shoes in a box. If he randomly picks shoes one by one (without replacement) from the box to get a red pair of shoes to wear, what is the maximum number of attempts he has to make ?

    • (a)27
    • (b)36
    • (c)44
    • (d)45

    UPSC's answer: (d) — Total shoes: 10 red pairs = 20 red shoes, 9 white pairs = 18 white shoes, 8 black pairs = 16 black shoes, so 54 shoes. To delay a red pair as long as possible, Raj can first pick all 34 non-red shoes (18 white + 16 black).

  5. Q5

    In how many ways can a batsman score exactly 25 runs by scoring single runs, fours and sixes only, irrespective of the sequence of scoring shots ?

    • (a)18
    • (b)19
    • (c)20
    • (d)21

    UPSC's answer: (b) — Let s, f and x be the numbers of singles, fours and sixes, so s + 4f + 6x = 25 with each at least 0; singles fill whatever is left, so every valid pair (f, x) gives exactly one way. x = 0: 4f ≤ 25, so f = 0 to 6 — 7 ways. x = 1: 4f ≤ 19, so f = 0 to 4 — 5 ways.

  6. Q6

    There are four letters and four envelopes and exactly one letter is to be put in exactly one envelope with the correct address. If the letters are randomly inserted into the envelopes, then consider the following statements : 1. It is possible that exactly one letter goes into an incorrect envelope. 2. There are only six ways in which only two letters can go into the correct envelopes. Which of the statements given above is/are correct ?

    • (a)1 only
    • (b)2 only
    • (c)Both 1 and 2
    • (d)Neither 1 nor 2

    UPSC's answer: (b) — Statement 1 is wrong: if three letters are in their correct envelopes, the only envelope left is the fourth letter's own, so exactly one letter can never be misplaced.

  7. Q7

    What is the remainder when 85 × 87 × 89 × 91 × 95 × 96 is divided by 100 ?

    • (a)0
    • (b)1
    • (c)2
    • (d)4

    UPSC's answer: (a) — The remainder on division by 100 is the last two digits of the product. 85 = 5 × 17 and 95 = 5 × 19 supply two factors of 5, and 96 = 2⁵ × 3 supplies more than two factors of 2. So 5² × 2² = 100 divides the product. Hence the remainder is 0, option (a).

  8. Q8

    What is the unit digit in the expansion of (57242)⁹ˣ⁷ˣ⁵ˣ³ˣ¹ ?

    • (a)2
    • (b)4
    • (c)6
    • (d)8

    UPSC's answer: (a) — The exponent is 9 × 7 × 5 × 3 × 1 = 945, and the unit digit of the base 57242 is 2. Unit digits of powers of 2 repeat in the cycle 2, 4, 8, 6 (period 4). 945 = 4 × 236 + 1, so the exponent leaves remainder 1 on division by 4. The unit digit is therefore the first in the cycle, 2 — option (a).

  9. Q9

    If ABC and DEF are both 3-digit numbers such that A, B, C, D, E and F are distinct non-zero digits such that ABC + DEF = 1111, then what is the value of A + B + C + D + E + F ?

    • (a)28
    • (b)29
    • (c)30
    • (d)31

    UPSC's answer: (d) — Since ABC and DEF are 3-digit numbers summing to 1111, the sum of their digits must account for the carries generated in each column. In the units column, C + F must equal 11 (to produce a digit 1 and carry 1 to the tens place), so C + F = 11.

  10. Q10

    D is a 3-digit number such that the ratio of the number to the sum of its digits is least. What is the difference between the digit at the hundred's place and the digit at the unit's place of D ?

    • (a)0
    • (b)7
    • (c)8
    • (d)9

    UPSC's answer: (c) — For D = 100a + 10b + c, the ratio D ÷ (a + b + c) is smallest when the hundreds digit is small and the other two digits are large. With hundreds digit 1, the number 199 gives 199 ÷ 19 ≈ 10.47; neighbours give more — 189 ÷ 18 = 10.5, 198 ÷ 18 = 11, 188 ÷ 17 ≈ 11.06.

  11. Q11

    Which one of the following statements best reflects the crucial message conveyed by the author of the passage ?

    • (a)Businesses that cause emissions may need to close down or pay for pollution in future.
    • (b)The only solution is technological development related to the issues of climate change.
    • (c)Waiting to deal with carbon emissions until technology improves is not a wise strategy.
    • (d)Since future technological change is uncertain, new industries should be based on renewable energy sources.

    UPSC's answer: (c) — The passage states that current emissions will affect the climate from the middle of the century onwards, creating immediate long-term consequences. It highlights that technological change is uncertain; it might make the transition away from fossil fuels cheap, or it might not.

  12. Q12

    Which one of the following statements best implies the most rational assumption that can be made from the passage ?

    • (a)We are likely to spend more money on cure than prevention.
    • (b)It is the job of the government to solve our environmental and public health problems.
    • (c)Health can be protected even if environmental problems go on unattended.
    • (d)Loss of traditional lifestyle and the influence of western values led to some unhealthy ways of living.

    UPSC's answer: (a) — The passage states that substantial lifestyle changes to reduce environmental or health problems are 'almost impossible to adopt' due to collective lethargy and perceived negligible individual impact.

  13. Q13

    Which one of the following statements best reflects the crux of the passage ?

    • (a)The scheme of Universal Basic Income should be implemented worldwide as a way of poverty alleviation.
    • (b)We must place food-based nutrition at the centre of our policy debate.
    • (c)Nutritional status of food should be improved by creating appropriate genetically modified crops.
    • (d)Using modern food processing technologies, we must fortify food items with required nutrient elements.

    UPSC's answer: (b) — The passage highlights that poor dietary choices and limited access to nutritious food are increasing non-communicable diseases and burdening health-care systems. It argues that this burden threatens economic progress, which is essential for poverty alleviation.

  14. Q14

    Three of the five positive integers p, q, r, s, t are even and two of them are odd (not necessarily in order). Consider the following : 1. p + q + r - s - t is definitely even. 2. 2p + q + 2r - 2s + t is definitely odd. Which of the above statements is/are correct ?

    • (a)1 only
    • (b)2 only
    • (c)Both 1 and 2
    • (d)Neither 1 nor 2

    UPSC's answer: (a) — There are exactly three even and two odd integers among p, q, r, s, t. In statement 1, subtraction does not change parity, so p + q + r - s - t has the same parity as p + q + r + s + t. The sum of three even numbers and two odd numbers is even, so statement 1 is definitely even.

  15. Q15

    Consider the following in respect of prime number p and composite number c. 1. (p + c)/(p - c) can be even. 2. 2p + c can be odd. 3. pc can be odd. Which of the statements given above are correct ?

    • (a)1 and 2 only
    • (b)2 and 3 only
    • (c)1 and 3 only
    • (d)1, 2 and 3

    UPSC's answer: (d) — Each statement says 'can be', so a single valid example proves it. Statement 1: p = 5, c = 15 gives (p + c)/(p − c) = 20/(−10) = −2, which is even. Statement 2: p = 2, c = 9 gives 2p + c = 13, which is odd (any odd composite c works). Statement 3: p = 3, c = 9 gives pc = 27, which is odd.

  16. Q16

    A 3-digit number ABC, on multiplication with D gives 37DD where A, B, C and D are different non-zero digits. What is the value of A + B + C ?

    • (a)18
    • (b)16
    • (c)15
    • (d)Cannot be determined due to insufficient data

    UPSC's answer: (a) — ABC × D = 37DD means ABC × D = 3700 + 11D, so ABC = (3700 + 11D) ÷ D must be a whole 3-digit number. D = 1, 2 or 3 makes ABC too large (over 999); so try D = 4 to 9. D = 4: 3744 ÷ 4 = 936 — digits 9, 3, 6 and 4 are all different and non-zero, so it works.

  17. Q17

    For any choices of values of X, Y and Z, the 6-digit number of the form XYZXYZ is divisible by :

    • (a)7 and 11 only
    • (b)11 and 13 only
    • (c)7 and 13 only
    • (d)7, 11 and 13

    UPSC's answer: (d) — XYZXYZ = XYZ × 1000 + XYZ = XYZ × 1001. 1001 = 7 × 11 × 13. So every number of this form is divisible by 7, 11 and 13, whatever the digits X, Y and Z. Hence option (d).

  18. Q18

    125 identical cubes are arranged in the form of a cubical block. How many cubes are surrounded by other cubes from each side ?

    • (a)27
    • (b)25
    • (c)21
    • (d)18

    UPSC's answer: (a) — 125 = 5 × 5 × 5, so the block is 5 cubes along each edge. A cube is surrounded on every side only if it does not lie on any outer face. Removing the outer layer on each side leaves an inner block of (5 − 2) × (5 − 2) × (5 − 2) = 3 × 3 × 3. That inner block has 27 cubes, option (a).

  19. Q19

    How many distinct 8-digit numbers can be formed by rearranging the digits of the number 11223344 such that odd digits occupy odd positions and even digits occupy even positions ?

    • (a)12
    • (b)18
    • (c)36
    • (d)72

    UPSC's answer: (c) — The number 11223344 contains two 1s, two 2s, two 3s, and two 4s. Odd digits are 1, 1, 3, 3 (four digits) and even digits are 2, 2, 4, 4 (four digits). There are 4 odd positions (1st, 3rd, 5th, 7th) and 4 even positions (2nd, 4th, 6th, 8th).

  20. Q20

    A, B, C working independently can do a piece of work in 8, 16 and 12 days respectively. A alone works on Monday, B alone works on Tuesday, C alone works on Wednesday; A alone, again works on Thursday and so on. Consider the following statements : 1. The work will be finished on Thursday. 2. The work will be finished in 10 days. Which of the above statements is/are correct ?

    • (a)1 only
    • (b)2 only
    • (c)Both 1 and 2
    • (d)Neither 1 nor 2

    UPSC's answer: (a) — The total work is taken as the LCM of 8, 16, and 12, which is 48 units, so A completes 6 units per day, B completes 3 units per day, and C completes 4 units per day.

  21. Q21

    Which one of the following statements best reflects the most logical and rational implication conveyed by the passage ?

    • (a)Arbitrary curbs on vehicles to reduce pollution are difficult to implement.
    • (b)Knee-jerk reactions cannot solve the problem of pollution but an evidence-based approach will be more effective.
    • (c)A heavy penalty should be enforced on those driving without periodic pollution tests.
    • (d)In the absence of laws to deal with the problems of pollution, the administration tends to make arbitrary decisions.

    UPSC's answer: (b) — The passage argues that drastic, arbitrary measures like odd-even schemes or banning specific vehicle types are ineffective because they do not address the root causes of pollution.

  22. Q22

    Which of the following statements best reflects the logical inference from the passage given above ?

    • (a)It is an important agenda of the countries around the world to ensure access to good external financing.
    • (b)Good corporate governance improves the credibility of the firms.
    • (c)International capital markets ensure that the firms maintain good corporate governance.
    • (d)Good corporate governance paves the way for robust supply chains.

    UPSC's answer: (b) — The passage states that effective corporate governance enhances access to external financing by firms. It further explains that investors place funds where standards of disclosure, timely and accurate financial reporting, and equal treatment are met.

  23. Q23

    Which one of the following statements best reflects the most logical and rational inference that can be drawn from the passage ?

    • (a)The home range of elephants needs to be a vast area of rich biodiversity.
    • (b)Elephants are the keystone species and they benefit the biodiversity.
    • (c)Rich biodiversity cannot be maintained in the forests without the presence of elephants.
    • (d)Elephants are capable of regenerating forests with species as per their requirement.

    UPSC's answer: (b) — The passage describes elephants as 'landscape architects' who create clearings, prevent overgrowth, and allow regeneration of other plant species.

  24. Q24

    If 7 ⊕ 9 ⊕ 10 = 8, 9 ⊕ 11 ⊕ 30 = 5, 11 ⊕ 17 ⊕ 21 = 13, what is the value of 23 ⊕ 4 ⊕ 15 ?

    • (a)6
    • (b)8
    • (c)13
    • (d)15

    UPSC's answer: (a) — Add the three numbers in each expression: 7+9+10=26, 9+11+30=50, 11+17+21=49. Add the digits of that sum: 2+6=8, 5+0=5, 4+9=13. Apply the same rule to 23+4+15=42. Add the digits: 4+2=6, so option (a) follows.

  25. Q25

    Let x be a positive integer such that 7x + 96 is divisible by x. How many values of x are possible ?

    • (a)10
    • (b)11
    • (c)12
    • (d)Infinitely many

    UPSC's answer: (c) — (7x + 96) ÷ x = 7 + 96 ÷ x, so x must divide 96 exactly. 96 = 2⁵ × 3, so the number of positive divisors is (5 + 1) × (1 + 1) = 12. They are 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48 and 96. Hence 12 values, option (c).

  26. Q26

    If p, q, r and s are distinct single digit positive numbers, then what is the greatest value of (p + q)(r + s) ?

    • (a)230
    • (b)225
    • (c)224
    • (d)221

    UPSC's answer: (b) — Let A = p + q and B = r + s; then A + B is the sum of four distinct digits from 1 to 9, so A + B ≤ 9 + 8 + 7 + 6 = 30. For any positive A and B with fixed sum T, the product AB is maximized when A and B are as close as possible, so AB ≤ (T/2)². Since T ≤ 30, AB ≤ (30/2)² = 225.

  27. Q27

    A number N is formed by writing 9 for 99 times. What is the remainder if N is divided by 13 ?

    • (a)11
    • (b)9
    • (c)7
    • (d)1

    UPSC's answer: (a) — N (ninety-nine 9s) = 10⁹⁹ − 1. Remainders of powers of 10 on division by 13: 10 → 10, 10² → 9, 10³ → 12 (that is, −1), so 10⁶ leaves 1 and the pattern repeats every 6. 99 = 6 × 16 + 3, so 10⁹⁹ leaves the same remainder as 10³, i.e. 12. N = 10⁹⁹ − 1 therefore leaves 12 − 1 = 11, option (a).

  28. Q28

    Each digit of a 9-digit number is 1. It is multiplied by itself. What is the sum of the digits of the resulting number ?

    • (a)64
    • (b)80
    • (c)81
    • (d)100

    UPSC's answer: (c) — The number is 111111111 (nine 1s). 111111111 × 111111111 = 12345678987654321. Its digits rise 1 to 9 and fall back to 1, so the digit sum is 2 × (1 + 2 + … + 8) + 9 = 2 × 36 + 9 = 81. Hence option (c).

  29. Q29

    What is the sum of all digits which appear in all the integers from 10 to 100 ?

    • (a)855
    • (b)856
    • (c)910
    • (d)911

    UPSC's answer: (b) — The integers from 10 to 100 consist of 91 numbers: 90 two-digit numbers (10-99) and one three-digit number (100). For the number 100, the sum of digits is 1 + 0 + 0 = 1.

  30. Q30

    ABCD is a square. One point on each of AB and CD; and two distinct points on each of BC and DA are chosen. How many distinct triangles can be drawn using any three points as vertices out of these six points ?

    • (a)16
    • (b)18
    • (c)20
    • (d)24

    UPSC's answer: (c) — There are 6 points in all: one on AB, one on CD, two on BC and two on DA. Any 3 of the 6 can be chosen in 6C3 = 20 ways. Three points fail to make a triangle only if they lie on one straight line; points on different sides of a square are never collinear, and no side holds three points.

  31. Q31

    Based on the above passage, the following assumptions have been made : 1. Collection, processing and segregation of municipal waste should be with government agencies. 2. Resource recovery and recycling require technological inputs that can be best handled by private sector enterprises. Which of the assumptions given above is/are correct ?

    • (a)1 only
    • (b)2 only
    • (c)Both 1 and 2
    • (d)Neither 1 nor 2

    UPSC's answer: (d) — Assumption 1 is not supported: the passage describes where the municipal budget goes (collection and transport) but never says that collection, processing and segregation should be with government agencies.

  32. Q32

    Which one of the following statements best reflects the crux of the passage ?

    • (a)Generation of energy from municipal solid waste is inexpensive.
    • (b)Biomethanation is the most ideal way of generating energy from municipal solid waste.
    • (c)Segregation of municipal solid waste is the first step in ensuring the success of waste-to-energy plants.
    • (d)The biodegradable component of India's municipal solid waste is not adequate to provide energy from waste efficiently/effectively.

    UPSC's answer: (c) — The passage explicitly states that waste-to-energy ideally fits in the chain 'after segregation' and 'before getting to the landfill'. It highlights that segregation at source is currently rare in India, implying it is a critical missing link.

  33. Q33

    Based on the above passage, the following assumptions have been made : 1. Organic farming is inherently unsafe for both farmers and consumers. 2. Farmers and consumers need to be educated about eco-friendly food. Which of the assumptions given above is/are correct ?

    • (a)1 only
    • (b)2 only
    • (c)Both 1 and 2
    • (d)Neither 1 nor 2

    UPSC's answer: (b) — The passage opens by reporting a claim that organic farming is inherently safer and healthier, and then questions it: in India the sector is young and poorly regulated.

  34. Q34

    Which one of the following statements best reflects the most logical, rational and practical message conveyed by the author of the passage ?

    • (a)In India, organic farming should not be promoted as a substitute for conventional farming.
    • (b)There are no safe organic alternatives to chemical fertilizers.
    • (c)In India, farmers need to be guided and helped to make their organic farming sustainable.
    • (d)The aim of organic farming should not be to generate huge profits as there is still no global market for its products.

    UPSC's answer: (c) — The passage highlights that the organic farming industry in India is young and lacks proper regulation, leading to confusion among farmers and consumers.

  35. Q35

    Based on the above passage, the following assumptions have been made : 1. To implement the Sustainable Development Goals and to achieve zero-hunger goal, monoculture agriculture practices are inevitable even if they do not address malnutrition. 2. Dependence on a few crops has negative consequences for human health and the ecosystem. 3. Government policies regarding food planning need to incorporate nutritional security. 4. For the present monoculture agriculture practices, farmers receive subsidies in various ways and government offers remunerative prices for grains and therefore they do not tend to consider crop diversity. Which of the above assumptions are valid ?

    • (a)1, 2 and 4 only
    • (b)2 and 3 only
    • (c)3 and 4 only
    • (d)1, 2, 3 and 4

    UPSC's answer: (b) — Assumption 1 is invalid because the passage explicitly states that monoculture practices perpetuate food and nutrition security problems, contradicting the idea that they are inevitable for achieving zero-hunger.

  36. Q36

    A box contains 14 black balls, 20 blue balls, 26 green balls, 28 yellow balls, 38 red balls and 54 white balls. Consider the following statements : 1. The smallest number n such that any n balls drawn from the box randomly must contain one full group of at least one colour is 175. 2. The smallest number m such that any m balls drawn from the box randomly must contain at least one ball of each colour is 167. Which of the above statements is/are correct ?

    • (a)1 only
    • (b)2 only
    • (c)Both 1 and 2
    • (d)Neither 1 nor 2

    UPSC's answer: (c) — To find the smallest n that guarantees a full group of at least one colour, we first find the maximum number of balls that can be drawn while still missing at least one ball of every colour: 13 black, 19 blue, 25 green, 27 yellow, 37 red, and 53 white, giving 13 + 19 + 25 + 27 + 37 + 53 = 174.

  37. Q37

    If 'ZERO' is written as 'CHUR', then how is 'PLAYER' written ?

    • (a)SOCAGT
    • (b)SODBGT
    • (c)SODBHT
    • (d)SODBHU

    UPSC's answer: (d) — In 'ZERO', each letter is shifted forward by 3 places in the alphabet: Z to C, E to H, R to U, O to R. Apply the same +3 shift to P, L, A, Y, E, R in 'PLAYER'. P+3=S, L+3=O, A+3=D, Y+3=B, E+3=H, R+3=U. Therefore 'PLAYER' is written as SODBHU, which is option (d).

  38. Q38

    Consider the following statements : 1. A is older than B. 2. C and D are of the same age. 3. E is the youngest. 4. F is younger than D. 5. F is older than A. How many statements given above are required to determine the oldest person/persons ?

    • (a)Only two
    • (b)Only three
    • (c)Only four
    • (d)All five

    UPSC's answer: (d) — Statement 3 establishes that E is the youngest, but this does not identify the oldest person among the others. Statement 2 states C and D are the same age, but without knowing their position relative to others, their age is undetermined.

  39. Q39

    Consider the following including the Question and the Statements : There are 5 members A, B, C, D, E in a family. Question : What is the relation of E to B ? Statement-1 : A and B are a married couple. Statement-2 : D is the father of C. Statement-3 : E is D's son. Statement-4 : A and C are sisters. Which one of the following is correct in respect of the above Question and Statements ?

    • (a)Statement-1, Statement-2 and Statement-3 are sufficient to answer the Question.
    • (b)Statement-1, Statement-3 and Statement-4 are sufficient to answer the Question.
    • (c)All four statements together are sufficient to answer the Question.
    • (d)All four statements are not sufficient to answer the Question.

    UPSC's answer: (c) — Statement-4 makes A and C sisters, so A is female and A and C have the same father. Statement-2 says D is the father of C, so D is the father of A. Statement-3 says E is D's son, so E is A's brother.

  40. Q40

    Choose the group which is different from the others :

    • (a)17, 37, 47, 97
    • (b)31, 41, 53, 67
    • (c)71, 73, 79, 83
    • (d)83, 89, 91, 97

    UPSC's answer: (d) — Option (a) contains 17, 37, 47, and 97, all of which are prime numbers. Option (b) contains 31, 41, 53, and 67, all of which are prime numbers. Option (c) contains 71, 73, 79, and 83, all of which are prime numbers.

  41. Q41

    With reference to the above passage, the following assumptions have been made : 1. Global warming is causing spring to come early and for longer durations. 2. Early spring and longer period of spring is not good for bird populations. Which of the above assumptions is/are correct ?

    • (a)1 only
    • (b)2 only
    • (c)Both 1 and 2
    • (d)Neither 1 nor 2

    UPSC's answer: (a) — The passage states that warmer winters with less snow result in a 'longer lag time' and a 'more protracted vernal window,' which supports the assumption that global warming is causing spring to last for longer durations.

  42. Q42

    Which one of the following statements best reflects the most logical, rational and crucial message implied by the passage ?

    • (a)An enhanced efficiency of use of nitrogen is imperative for both food production and environment.
    • (b)Production of synthetic nitrogen fertilizers cannot be stopped as it will adversely affect global food security.
    • (c)Alternatives to crops that require excess of nitrogen should be identified and cultivated.
    • (d)Conventional agriculture using synthetic fertilizers should be replaced with agroforestry, agroecosystems and organic farming.

    UPSC's answer: (a) — The passage highlights that the global average nitrogen use efficiency is only 0.4, meaning 60% of added nitrogen is lost to the environment as pollution.

  43. Q43

    Which one of the following statements best reflects the most logical, rational and crucial message conveyed by the passage ?

    • (a)Climate justice should be ingrained in detail in the rules of all the new climate compacts/agreements.
    • (b)Environmental resources are unevenly distributed and exploited across the globe.
    • (c)There is an impending issue of dealing with a huge number of climate change victims/climate refugees.
    • (d)Climate change in all its connotations is mostly due to developed countries and therefore their share of burden should be more.

    UPSC's answer: (a) — The passage identifies climate justice as a significant principle that has 'eluded consensus' in past climate change summits and compacts. It defines the scope of climate justice to include mitigation, adaptation support, and compensation for loss and damage, not just mitigation.

  44. Q44

    A principal P becomes Q in 1 year when compounded half-yearly with R% annual rate of interest. If the same principal P becomes Q in 1 year when compounded annually with S% annual rate of interest, then which one of the following is correct ?

    • (a)R = S
    • (b)R > S
    • (c)R < S
    • (d)R ≤ S

    UPSC's answer: (c) — Half-yearly compounding at R% a year for one year: Q = P × (1 + R/200) × (1 + R/200). Annual compounding at S%: Q = P × (1 + S/100). Equating: 1 + S/100 = 1 + R/100 + R²/40000, so S = R + R²/400. For any positive rate R²/400 > 0, so S is strictly greater than R — option (c), R < S.

  45. Q45

    How many natural numbers are there which give a remainder of 31 when 1186 is divided by these natural numbers ?

    • (a)6
    • (b)7
    • (c)8
    • (d)9

    UPSC's answer: (d) — If 1186 leaves remainder 31 on division by n, then n divides 1186 − 31 = 1155, and n must be greater than 31. 1155 = 3 × 5 × 7 × 11, which has 2 × 2 × 2 × 2 = 16 divisors. The divisors up to 31 are 1, 3, 5, 7, 11, 15 and 21 — seven of them.

  46. Q46

    Let pp, qq and rr be 2-digit numbers where p < q < r. If pp + qq + rr = tt0, where tt0 is a 3-digit number ending with zero, consider the following statements : 1. The number of possible values of p is 5. 2. The number of possible values of q is 6. Which of the above statements is/are correct ?

    • (a)1 only
    • (b)2 only
    • (c)Both 1 and 2
    • (d)Neither 1 nor 2

    UPSC's answer: (c) — pp, qq, rr are repdigits, so pp=11p, qq=11q, rr=11r, and tt0=110t. Equation gives 11(p+q+r)=110t, hence p+q+r=10t. Since p,q,r are distinct digits 1 to 9 with p<q<r, their sum can only be 10 or 20.

  47. Q47

    What is the sum of all 4-digit numbers less than 2000 formed by the digits 1, 2, 3 and 4, where none of the digits is repeated ?

    • (a)7998
    • (b)8028
    • (c)8878
    • (d)9238

    UPSC's answer: (a) — The 4-digit numbers must be less than 2000, so the thousands digit must be 1. The remaining three digits (2, 3, 4) can be arranged in the hundreds, tens, and units places in 3! = 6 ways. The sum of the digits in the thousands place is 1 × 6 = 6.

  48. Q48

    What is the number of selections of 10 consecutive things out of 12 things in a circle taken in the clockwise direction ?

    • (a)3
    • (b)11
    • (c)12
    • (d)66

    UPSC's answer: (c) — In a circle of 12 things, a block of 10 consecutive things taken clockwise is fixed completely by its starting point. Any of the 12 things can be the starting point, and each start gives a different block (because 10 is less than 12).

  49. Q49

    If today is Sunday, then which day is it exactly on 10¹⁰ th day ?

    • (a)Wednesday
    • (b)Thursday
    • (c)Friday
    • (d)Saturday

    UPSC's answer: (a) — The key treats today (Sunday) as day 1, so the 10¹⁰th day falls 10¹⁰ − 1 days after today. Remainders of 10ⁿ on division by 7 repeat every 6 (10 → 3, 10² → 2, 10³ → 6, 10⁴ → 4, 10⁵ → 5, 10⁶ → 1); since 10 = 6 + 4, 10¹⁰ leaves the same remainder as 10⁴, which is 4.

  50. Q50

    There are three traffic signals. Each signal changes colour from green to red and then from red to green. The first signal takes 25 seconds, the second signal takes 39 seconds and the third signal takes 60 seconds to change the colour from green to red. The durations for green and red colours are same. At 2:00 p.m, they together turn green. At what time will they change to green next, simultaneously ?

    • (a)4:00 p.m.
    • (b)4:10 p.m.
    • (c)4:20 p.m.
    • (d)4:30 p.m.

    UPSC's answer: (b) — Each signal's full cycle (green to red and back to green) is twice the given green-to-red duration: Signal 1 = 50s, Signal 2 = 78s, Signal 3 = 120s. The signals turn green simultaneously again after the Least Common Multiple (LCM) of their cycle durations.

  51. Q51

    Which one of the following statements best reflects the most logical and rational message conveyed by the author of the passage ?

    • (a)Food yielding trees should replace other trees in rural and tribal areas and community owned lands.
    • (b)Food security cannot be ensured in India with the present practice of conventional agriculture.
    • (c)Wastelands and degraded areas in India should be converted into agroforestry systems to help the poor.
    • (d)Agroecosystems should be developed in addition to or along with conventional agriculture.

    UPSC's answer: (d) — The passage explicitly states that sourcing food from non-agricultural lands (like forests and wetlands) 'in addition to' agricultural lands enables a systemic approach to food consumption.

  52. Q52

    Which one of the following statements best reflects the most logical and practical message conveyed by the passage ?

    • (a)It is necessary to put proper effluent treatment protocols in place.
    • (b)It is necessary to promote environmental awareness among people.
    • (c)Spread of drug-resistant bacteria cannot be done away with, as it is inherent in modern medical care.
    • (d)Pharma-manufacturing companies should be set up in remote rural areas, away from crowded towns and cities.

    UPSC's answer: (a) — The passage explicitly identifies the 'environmental impact of antibiotics-manufacturing companies not treating their waste' as the primary, under-discussed issue. It establishes a direct causal link between this untreated waste and the rise of drug-resistant infections around pharma plants.

  53. Q53

    Which one of the following statements best reflects the crux of the passage ?

    • (a)To become a global power, India needs to invest in universal quality education.
    • (b)India is unable to become a global power because it is not focussing or promoting knowledge economy.
    • (c)Our education system should focus more on imparting skills during higher education.
    • (d)Parents of many school children are illiterate and are unaware of the benefits of quality education.

    UPSC's answer: (a) — The passage argues that the benefits of good quality school education are realized only when students acquire foundational 'gateway skills' before moving to advanced levels.

  54. Q54

    40 children are standing in a circle and one of them (say child-1) has a ring. The ring is passed clockwise. Child-1 passes on to child-2, child-2 passes on to child-4, child-4 passes on to child-7 and so on. After how many such changes (including child-1) will the ring be in the hands of child-1 again ?

    • (a)14
    • (b)15
    • (c)16
    • (d)17

    UPSC's answer: (b) — The ring moves 1, then 2, then 3 places, and so on, so after n passes it has moved 1 + 2 + … + n = n(n + 1)/2 places. It is back with child-1 when this total is a multiple of 40. n = 14 gives 105 (child 26 — not a multiple of 40); n = 15 gives 120 = 3 × 40.

  55. Q55

    What is the middle term of the sequence Z, Z, Y, Y, Y, X, X, X, X, W, W, W, W, W, ..., A ?

    • (a)H
    • (b)I
    • (c)J
    • (d)M

    UPSC's answer: (b) — Z appears 2 times, Y 3 times, X 4 times and so on, so the k-th letter from Z appears k + 1 times, down to A (the 26th) appearing 27 times. Total terms = 2 + 3 + … + 27 = 377, so the middle term is the 189th.

  56. Q56

    Question : Is p greater than q ? Statement-1 : p × q is greater than zero. Statement-2 : p² is greater than q². Which one of the following is correct in respect of the above Question and the Statements ?

    • (a)The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone.
    • (b)The Question can be answered by using either Statement alone.
    • (c)The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone.
    • (d)The Question cannot be answered even by using both the Statements together.

    UPSC's answer: (d) — Statement 1 states that p × q > 0, which implies that p and q have the same sign (both positive or both negative), but it does not determine their relative magnitudes.

  57. Q57

    Question : Is (p + q - r) greater than (p - q + r), where p, q and r are integers ? Statement-1 : (p - q) is positive. Statement-2 : (p - r) is negative. Which one of the following is correct in respect of the above Question and the Statements ?

    • (a)The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone.
    • (b)The Question can be answered by using either Statement alone.
    • (c)The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone.
    • (d)The Question cannot be answered even by using both the Statements together.

    UPSC's answer: (c) — The question asks if (p + q - r) > (p - q + r), which simplifies to 2q > 2r, or q > r. Statement 1 states (p - q) > 0, implying p > q. This does not provide any information about the relationship between q and r, so it is insufficient alone. Statement 2 states (p - r) < 0, implying p < r.

  58. Q58

    In a party, 75 persons took tea, 60 persons took coffee and 15 persons took both tea and coffee. No one taking milk takes tea. Each person takes at least one drink. Question : How many persons attended the party ? Statement-1 : 50 persons took milk. Statement-2 : Number of persons who attended the party is five times the number of persons who took milk only. Which one of the following is correct in respect of the above Question and the Statements ?

    • (a)The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone.
    • (b)The Question can be answered by using either Statement alone.
    • (c)The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone.
    • (d)The Question cannot be answered even by using both the Statements together.

    UPSC's answer: (a) — From the given data, tea drinkers = 75, coffee drinkers = 60, and tea ∩ coffee = 15, so the number of people who take tea or coffee (or both) is 75 + 60 − 15 = 120.

  59. Q59

    Consider a 3-digit number. Question : What is the number ? Statement-1 : The sum of the digits of the number is equal to the product of the digits. Statement-2 : The number is divisible by the sum of the digits of the number. Which one of the following is correct in respect of the above Question and the Statements ?

    • (a)The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone.
    • (b)The Question can be answered by using either Statement alone.
    • (c)The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone.
    • (d)The Question cannot be answered even by using both the Statements together.

    UPSC's answer: (d) — Let the 3-digit number have digits a, b, c (a from 1 to 9, b and c from 0 to 9). Statement 1 requires a + b + c = a × b × c. If any digit is 0 the product is 0 while the sum is at least 1, so all digits are at least 1. Setting one digit to 1 and the other two to p and q gives 1 + p + q = pq, i.e.

  60. Q60

    For five children with ages a < b < c < d < e; any two successive ages differ by 2 years. Question : What is the age of the youngest child ? Statement-1 : The age of the eldest is 3 times the youngest. Statement-2 : The average age of the children is 8 years. Which one of the following is correct in respect of the above Question and the Statements ?

    • (a)The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone.
    • (b)The Question can be answered by using either Statement alone.
    • (c)The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone.
    • (d)The Question cannot be answered even by using both the Statements together.

    UPSC's answer: (b) — Let the ages of the five children be a, a+2, a+4, a+6, and a+8, where 'a' is the age of the youngest child. Using Statement-1: The eldest child's age is a+8. The statement says a+8 = 3a, which simplifies to 2a = 8, giving a = 4. This uniquely determines the youngest child's age.

  61. Q61

    Which one of the following statements best reflects the most logical message implied by the above passage ?

    • (a)Modern technology enfeebles societal structure and makes life difficult.
    • (b)Modern life is full of uncertainties and endless difficult choices.
    • (c)We are influenced by the opinion of others and have no courage to follow our own convictions.
    • (d)In our lives, having too few choices may not be a good thing, but having too many can be equally as difficult.

    UPSC's answer: (d) — The passage introduces the 'paradox of choice' using the story of Buridan's ass, which starves because it cannot choose between two equally appealing options. It states that modern technology and constant connectivity exacerbate the 'glut of choices,' making decisions more difficult.

  62. Q62

    Regarding the financialization of household savings, which of the following statements best reflect the solutions that are implied by the passage ? 1. A flexible environment is needed to develop solutions. 2. Households need customised solutions. 3. Innovations in financial technology are required. Select the correct answer using the code given below :

    • (a)1 and 2 only
    • (b)2 and 3 only
    • (c)1 and 3 only
    • (d)1, 2 and 3

    UPSC's answer: (d) — The passage identifies 'onerous bureaucracy' as a hurdle, implying that a 'flexible environment' is needed to develop solutions, supporting statement 1.

  63. Q63

    Based on the above passage, the following assumptions have been made : 1. Patent protection given to patentees puts a huge burden on public's purchasing power in accessing patented medicines. 2. Dependence on other countries for pharmaceutical products is a huge burden for developing and poor countries. 3. Providing medicines to the public at affordable prices is a key goal during the public health policy design in many countries. 4. Governments need to find an appropriate balance between the rights of patentees and the requirements of the patients. Which of the above assumptions are valid ?

    • (a)1 and 2
    • (b)1 and 4
    • (c)3 and 4
    • (d)2 and 3

    UPSC's answer: (b) — Assumption 1 is valid because the passage explicitly states that patentees determine prices which 'could be unaffordable to the public,' implying a burden on purchasing power.

  64. Q64

    Based on the above passage, the following assumptions have been made : 1. Protection of privacy is not just a right, but it has value to the economy. 2. There is a fundamental link between privacy and innovation. Which of the above assumptions is/are valid ?

    • (a)1 only
    • (b)2 only
    • (c)Both 1 and 2
    • (d)Neither 1 nor 2

    UPSC's answer: (c) — The passage explicitly states that India must ensure digital economy growth while keeping personal data secure, directly linking privacy protection to economic value, which validates Assumption 1.

  65. Q65

    In an examination, the maximum marks for each of the four papers namely P, Q, R and S are 100. Marks scored by the students are in integers. A student can score 99% in n different ways. What is the value of n ?

    • (a)16
    • (b)17
    • (c)23
    • (d)35

    UPSC's answer: (d) — The total maximum marks for the four papers P, Q, R, and S is 400. Scoring 99% means the student must obtain exactly 396 marks (0.99 * 400). This is equivalent to losing exactly 4 marks from the maximum possible score (400 - 396 = 4).

  66. Q66

    A flag has to be designed with 4 horizontal stripes using some or all of the colours red, green and yellow. What is the number of different ways in which this can be done so that no two adjacent stripes have the same colour ?

    • (a)12
    • (b)18
    • (c)24
    • (d)36

    UPSC's answer: (c) — The first stripe can be any of the 3 colours. Each later stripe must differ from the one just above it, leaving 2 choices each for stripes 2, 3 and 4. Total = 3 × 2 × 2 × 2 = 24. ('Some or all' colours is automatically satisfied, since at least two colours are always used.) Hence option (c).

  67. Q67

    A rectangular floor measures 4 m in length and 2·2 m in breadth. Tiles of size 140 cm by 60 cm have to be laid such that the tiles do not overlap. A tile can be placed in any orientation so long as its edges are parallel to the edges of the floor. What is the maximum number of tiles that can be accommodated on the floor ?

    • (a)6
    • (b)7
    • (c)8
    • (d)9

    UPSC's answer: (d) — Floor: 400 cm × 220 cm = 88,000 cm²; tile: 140 cm × 60 cm = 8,400 cm². Area alone would allow at most 10 tiles, but the shapes do not allow that many. Simple layouts give only 8, e.g. six tiles laid lengthwise in a 280 × 180 block plus two upright tiles in the remaining 120 cm strip.

  68. Q68

    There are five persons P, Q, R, S and T each one of whom has to be assigned one task. Neither P nor Q can be assigned Task-1. Task-2 must be assigned to either R or S. In how many ways can the assignment be done ?

    • (a)6
    • (b)12
    • (c)18
    • (d)24

    UPSC's answer: (d) — Five people take five tasks with one task each, so an assignment is a one-to-one matching of the five people to the five tasks. Task-2 must go to R or S, which splits the count into two cases. Take Task-2 = R.

  69. Q70

    Consider the following : I. A + B means A is neither smaller nor equal to B. II. A - B means A is not greater than B. III. A × B means A is not smaller than B. IV. A ÷ B means A is neither greater nor equal to B. V. A ± B means A is neither smaller nor greater than B. Statement : P × Q, P - T, T ÷ R, R ± S Conclusion-1 : Q ± T Conclusion-2 : S + Q Which one of the following is correct in respect of the above Statement and the Conclusions ?

    • (a)Only Conclusion-1 follows from the Statement.
    • (b)Only Conclusion-2 follows from the Statement.
    • (c)Both Conclusion-1 and Conclusion-2 follow from the Statement.
    • (d)Neither Conclusion-1 nor Conclusion-2 follows from the Statement.

    UPSC's answer: (b) — Translate the codes: '×' means ≥, '-' means ≤, '÷' means <, '±' means =, and '+' means >. The statement P × Q, P - T, T ÷ R, R ± S translates to P ≥ Q, P ≤ T, T < R, and R = S. Combining these gives the chain: Q ≤ P ≤ T < R = S, which simplifies to Q < S. Conclusion-1 states Q ± T (Q = T).

  70. Q71

    Which one of the following statements most likely reflects as to what the author of the passage intends to say ?

    • (a)Enrolment in schools and colleges is high but there is no quality education.
    • (b)Unemployment must be seen as a function of rising education and aspirations of young Indians.
    • (c)There are no labour-intensive industries to accommodate the huge number of unemployed people.
    • (d)The education system should be properly designed so as to enable the educated people to be self-employed.

    UPSC's answer: (b) — The passage states that the standard unemployment rate is an inaccurate measure of economic performance in India due to rising school and college enrolment.

  71. Q72

    Which one of the following statements best reflects the most rational, logical and practical message conveyed by the passage ?

    • (a)Modern statesmen need to be well trained in scientific methods and philosophical thinking to enable them to have a better perspective of their roles, responsibilities and goals.
    • (b)It is not desirable to have Governments managed by empirical statesmen unless well mixed with others who are grounded in learning and reflect wisdom.
    • (c)As the statesmen/bureaucrats are the products of a society, it is desirable to have a system of education in a society that focuses on training its citizens in scientific method and philosophical thinking from a very early age.
    • (d)It is desirable that all scientists need to be philosophers as well to make their work goal-oriented and thus purposeful and useful to the society.

    UPSC's answer: (b) — The passage argues that both science and government require an external guiding force (philosophy/statesmanship) to coordinate their efforts and set correct goals, preventing them from becoming superficial or destructive.

  72. Q73

    Based on the above passage, which one of the following terms best expresses the ultimate goal of the state ?

    • (a)Personal safety
    • (b)Health of body and mind
    • (c)Communal harmony
    • (d)Liberty

    UPSC's answer: (d) — The passage explicitly states that the end of the state is to 'free each man from fear' so he may live with 'full security'. It further clarifies that the goal is to enable bodies and minds to function safely, not to restrain or dominate.

  73. Q74

    What is the remainder if 2¹⁹² is divided by 6 ?

    • (a)0
    • (b)1
    • (c)2
    • (d)4

    UPSC's answer: (d) — Powers of 2 on division by 6 leave remainders 2, 4, 2, 4, … : 2¹ → 2, 2² → 4, 2³ = 8 → 2, 2⁴ = 16 → 4. Odd powers leave 2 and even powers leave 4. 192 is even, so 2¹⁹² leaves remainder 4. Hence option (d).

  74. Q75

    Consider the sequence ABC_ _ ABC_ DABBCD_ ABCD that follows a certain pattern. Which one of the following completes the sequence ?

    • (a)DACB
    • (b)CDAB
    • (c)DCCA
    • (d)DDCA

    UPSC's answer: (d) — The sequence is composed of four 4-letter blocks: 'ABC_', '_ABC', '_DAB', 'BCD_'. Analyzing the first block 'ABC_', the missing letter must be 'D' to form the set {A, B, C, D}, making it 'ABCD'.

  75. Q76

    AB and CD are 2-digit numbers. Multiplying AB with CD results in a 3-digit number DEF. Adding DEF to another 3-digit number GHI results in 975. Further A, B, C, D, E, F, G, H, I are distinct digits. If E = 0, F = 8, then what is A + B + C equal to ?

    • (a)6
    • (b)7
    • (c)8
    • (d)9

    UPSC's answer: (a) — Since E = 0 and F = 8, the product DEF is D08, which is a 3-digit number ending in 8. The sum DEF + GHI = 975 implies D08 + GHI = 975, so GHI = 975 - D08.

  76. Q77

    Consider the following statements in respect of five candidates P, Q, R, S and T. Two statements are true and one statement is false. True Statement : One of P and Q was selected for the job. False Statement : At least one of R and S was selected for the job. True Statement : At most two of R, S and T were selected for the job. Which of the following conclusions can be drawn ? 1. At least four were selected for the job. 2. S was selected for the job. Select the correct answer using the code given below :

    • (a)1 only
    • (b)2 only
    • (c)Both 1 and 2
    • (d)Neither 1 nor 2

    UPSC's answer: (d) — The false statement 'At least one of R and S was selected' implies that neither R nor S was selected for the job. Since R and S are not selected, the condition 'At most two of R, S and T were selected' is automatically satisfied regardless of T's status, as the count of selected candidates among…

  77. Q78

    Let P, Q, R, S and T be five statements such that : I. If P is true, then both Q and S are true. II. If R and S are true, then T is false. Which of the following can be concluded ? 1. If T is true, then at least one of P and R must be false. 2. If Q is true, then P is true. Select the correct answer using the code given below :

    • (a)1 only
    • (b)2 only
    • (c)Both 1 and 2
    • (d)Neither 1 nor 2

    UPSC's answer: (a) — Statement I is P → (Q and S), so P true forces S true. Statement II is (R and S) → not T, so if T is true, R and S cannot both be true. If T is true and both P and R were true, P true would make S true, so R and S would both be true.

  78. Q79

    A cuboid of dimensions 7 cm × 5 cm × 3 cm is painted red, green and blue colour on each pair of opposite faces of dimensions 7 cm × 5 cm, 5 cm × 3 cm, 7 cm × 3 cm respectively. Then the cuboid is cut and separated into various cubes each of side length 1 cm. Which of the following statements is/are correct ? 1. There are exactly 15 small cubes with no paint on any face. 2. There are exactly 6 small cubes with exactly two faces, one painted with blue and the other with green. Select the correct answer using the code given below :

    • (a)1 only
    • (b)2 only
    • (c)Both 1 and 2
    • (d)Neither 1 nor 2

    UPSC's answer: (a) — The cuboid dimensions are 7 cm × 5 cm × 3 cm, so the number of unpainted cubes (interior) is (7-2) × (5-2) × (3-2) = 5 × 3 × 1 = 15, making statement 1 correct. The faces are painted as follows: 7×5 faces are Red, 5×3 faces are Green, and 7×3 faces are Blue.

Question paper and answer key: Union Public Service Commission. Explanations: UPSC Answer Check. Practise this paper with a timer →

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