UPSC 2024 CSAT PYQs with Answers

Q − S = 2S gives Q = 3S. Among the numbers 4, 5, 10, 12 and 15, only S = 5 with Q = 15 satisfies this. Next, T = R + S + 3 = R + 8; trying the remaining numbers {4, 10, 12}, only R = 4 gives T = 12, which is valid. The leftover number is P = 10. Therefore P + R − T = 10 + 4 − 12 = 2.

The successive differences are 11, 25, 45, ..., and these differences grow by 14, 20, 26, 32. So the differences are 11, 25, 45, 71, 103 and the sequence is 3, 14, 39, 84, 155, 258. Hence * = 155.

The code writes the word in reverse and adds A at the beginning: POT reversed is TOP, giving ATOP; TRAP reversed is PART, giving APART. Hence ARENA reversed is ANERA, giving AANERA.

The code multiplies the positions of the letters: A(1) x B(2) x C(3) x D(4) = 24, and E x F x G x H = 5 x 6 x 7 x 8 = 1680. Hence IJKL = 9 x 10 x 11 x 12 = 11880.

2x >= 3y and 3x = 4z give 9y <= 8z, so 9y > 8z is false. But x < y and y <= z imply x < z, i.e. x is not greater than z (x R z) is true. Only statement 2 is correct.

-25. Replace the symbols as given: + becomes -, - becomes x, x becomes /, and / becomes +. Thus 10 + 30 - 100 x 50 / 25 becomes 10 - 30 x 100 / 50 + 25. Apply normal precedence: 30 x 100 / 50 = 60. So the value is 10 - 60 + 25 = -25.

The main statement says Pradeep becomes either a Director or a Producer. Statement S (not a Producer) forces him to be a Director, so SP is consistent. Statement R (not a Director) forces him to be a Producer, so RQ is consistent. Hence both SP and RQ.

Let P's age be 10a + b and Q's be 10b + a. Statement I (P > Q) gives a > b but not the difference, so it is not sufficient. Statement II: sum/difference = 11/6 gives 11(a + b) = (11/6) x 9(a - b), i.e., a + b = (3/2)(a - b), so a = 5b. With digits, b = 1 and a = 5, giving ages 51 and 15 and difference 36. Hence one of the statements alone (Statement II) is sufficient.

Assumption 1 is not valid: the passage says the flower flaunts its petals and perfume to attract insects for pollination, not as a luxury of Nature. Assumption 2 is not valid either: the flower's real usefulness is attracting pollinators - its beauty is called a by-product and a human invention. Hence neither is valid.

The passage says poetry abides by the plurality of life and existence, while those who claim absolute truths turn dictatorial and tyrannical. In a world marked by tyranny and bigotry, poetry - which does not expect belief in absolute truths - becomes a form of dynamic resistance.

Statement I: P + Q = R + S. Statement II: P + S > Q + R. From I and II we can only derive relationships among the four totals, not the individual comparison of P and Q; adding the inequalities does not isolate P > Q or Q > P. The question cannot be answered even with both statements.

The three articles cost Rs. 50, with q = Rs. 16, so p + r = 34. Statement I alone allows p <= 17; Statement II alone allows p >= 17. Together they force p = 17. Both statements are needed, and together they answer the question.

Checking distinct-prime triples whose sum is a prime less than 23: any triple containing 2 has an even sum greater than 2 (composite), and the only remaining candidate is (3, 5, 11) with sum 19, which is prime. So Statement I alone identifies the numbers. Statement II (one number is 5) is not unique. Hence one of the statements alone is sufficient.

Statement I gives only the highest and lowest marks, and Statement II says their removal does not change the average. This does not determine how many students there are, since the count of the remaining students is unknown. Hence the question cannot be answered even using both statements together.

Statement I: X = 4/5 (Y + Z). Statement II: Y = 2/7 (X + Z). Solving together: from I, Z = (5X - 4Y)/4; substituting into II gives 7Y = 2X + (5X - 4Y)/2, i.e. 18Y = 9X, so X = 2Y, and then Z = 1.5Y. So Y received the least. Both statements together are required.

From Statement II, the possible pairs are (1,12), (2,6) and (3,4). Statement I requires x/y to be an odd integer; only (6,2) satisfies this because 6/2 = 3 is odd. Hence both statements together determine x = 6 and y = 2.

The passage says growth strategies must be rethought for a resource-constrained world, with resource- and energy-intensive processes making way for efficient, resource-frugal ones that protect the environment available to the poor and vulnerable. The message is that maintaining high environmental standards is now a prerequisite for achieving steady, sufficient and inclusive growth.

The passage warns that connected home device manufacturers and service providers will gather more personal data, with or without consent, turning the home into a corporate storefront. The clear implication is that interconnected devices can be at security risk and home users may have privacy risk.

The passage says that in a robust democracy reality must find transparent expression through the media and deliberative articulation, with a normatively responsible media playing its role. The message is that responsible media should not distort the real in an ideal democracy.

Time = size / rate. The size (12 MB = 12 x 1024 = 12,288 KB) comes from Statement I and the transfer rate (2.4 KB/s) from Statement II. Time = 12,288 / 2.4 = 5,120 seconds. Both statements together are needed to compute the download time.

Statement I (m + n > mn with m > n) forces n = 1, because for m > n >= 2 the product mn is at least m + n. But it leaves m free. Statement II gives the pairs (1,24), (2,12), (3,8), (4,6). Together, only (m, n) = (24, 1) satisfies both. Hence both statements together are sufficient.

India being the largest producer of milk does not imply that it is the largest exporter of milk (I), nor that it does not import milk (II). Hence neither conclusion follows.

North-East. Starting westward, a left turn makes the person face south. From south, a 225 degree clockwise turn is the same as turning 180 degree to north and then 45 degree more to north-east. Therefore the final direction is North-East.

Working backwards from an office in the North-East, take the initial direction as South: 100 m South, turn left (East) 100 m, turn left (North) 300 m, turn right (East) 100 m gives a net 200 m North and 200 m East - exactly North-East of the house. Hence he initially walked South.

For k = 3, the pair is uniquely (1,2); for k = 4 it is uniquely (1,3). For k = 5, both (1,4) and (2,3) satisfy p < q and p + q = 5, so p and q are not uniquely determined. Hence the smallest such k is 5.

3^25 + 3^27 = 3^25(1 + 3^2) = 10 x 3^25, which is exactly divisible by 10.

The passage says caterpillar frass induces the plant to turn off its defence against pests, and that the find could throw light on compounds associated with plant response to pathogens. The practical implication is that this finding can help in the development of organic, ecologically sustainable pesticides.

The passage says giant icebergs store up to 20 percent of carbon in the Southern Ocean (1) and that their meltwater, rich in iron and nutrients, supports unexpectedly high phytoplankton productivity (2). Both statements are supported by the passage.

The experiment converted carbon dioxide into solid limestone inside basalt rocks - the carbon dioxide is literally converted into stone. The logical and practical suggestion is that this can be used as one of the methods of carbon sequestration.

Let orange, mango and apple cost o, m and a. 4o + 6m + 8a = 2(o + 2m + 5a) simplifies to 2o + 2m = 2a, i.e., o + m = a, so statement 2 is correct. Then 3o + 5m + 9a = 3o + 5m + 9(o + m) = 12o + 14m, and 4o + 6m + 8a = 4o + 6m + 8(o + m) = 12o + 14m, so statement 1 is also correct. Hence both statements are correct.

Four triplets. The first seven natural numbers are 1 to 7. Since x > 2y > 3z, z must be small. If z = 1, then 2y > 3, so y can be 2 or 3. For y = 2, x > 4 gives x = 5, 6 or 7. For y = 3, x > 6 gives x = 7. If z >= 2, then 3z >= 6 and 2y must be greater than 6, forcing y >= 4 and x > 8, impossible in 1 to 7. Thus four triplets are possible: (5,2,1), (6,2,1), (7,2,1), (7,3,1).

Both A = 9 (e.g. 91 + 86 = 177) and A = 8 (e.g. 81 + 96 = 177) work with distinct digits, so the value of A cannot be determined uniquely.

Let Q cost q. Then R costs 1.2q and P costs 1.25 x 1.2q = 1.5q. Total = q + 1.2q + 1.5q = 3.7q = 3330, so q = 900. Hence P costs 1.5 x 900 = Rs. 1,350.

The sequence consists of blocks 1; 1,2; 1,3,2; 1,4,3,2; ... where the k-th block sums to 1 + 2 + ... + k = k(k+1)/2. The first 28 terms are blocks 1 to 7, and their total is 1 + 3 + 6 + 10 + 15 + 21 + 28 = 84.

56. Count digit 5 in units and tens places from 1 to 260. Units place: 5, 15,., 255 gives 26 occurrences. Tens place: 50-59, 150-159 and 250-259 give 10 + 10 + 10 = 30 occurrences. Total = 26 + 30 = 56.

The passage says parents' solicitude is often a disguise for love of power, that they consider adolescent moral problems their province, and that they are so dogmatic the young seldom confide in them. The implication is that parents in general may not be of much help when children are on their way to becoming adults.

Assumption 1 is valid: parental solicitude is called a disguise for love of power, and parents are so dogmatic that the young seldom confide in them - the adolescent feels uncomfortable because parents tend to be dominating and assertive. Assumption 2 is not: the passage says nothing about the adolescent's respect for parents.

Assumption 1 contradicts the passage: the tyranny of the fixed-duration classroom leaving learners behind is precisely why change is needed. Assumption 2 contradicts it too: only about 10 percent employability in graduates shows the system does not produce enough skilled workers. Hence neither is valid.

The passage says the classroom model emphasizes fixed duration over learning effectiveness, subjecting every learner to the same lectures in the same way (1), and that this one-size-fits-all script leaves most learners behind (2). Both inferences are valid.

17.5. At 4:25, the minute hand is at 25 x 6 = 150 degrees. The hour hand is at 4 x 30 + 25 x 0.5 = 132.5 degrees. The angle between them is 150 - 132.5 = 17.5 degrees.

p and q are odd; r and s are even. Statement 1: (p - r)^2 is odd and qs is even, so their product is even - correct. Statement 2: (q - s) is odd, q^2 is odd and s is even, so the product is even - correct. Statement 3: (q + r)^2 is odd and (p + s) is odd, so their product is odd - correct. Hence all three statements are correct.

2025 is a non-leap year beginning on Wednesday. From 2025 to 2031 there are six years including one leap year (2028), an offset of 6 + 1 = 7 days, so 2031 also begins on Wednesday and is non-leap. Hence the calendar of 2025 matches that of 2031.

3 times. Clock hands coincide once every 720/11 minutes. Between 10:00 a.m. and 2:00 p.m., the overlaps occur roughly at 10:54, 12:00 and 1:05. Thus they coincide 3 times.

42. The source equality is: weight of 6 boys = weight of 7 girls = weight of 3 men = weight of 4 women. The average weight of a woman is 63 kg, so 4 women weigh 4 x 63 = 252 kg. Therefore 6 boys also weigh 252 kg. Average weight of a boy = 252/6 = 42 kg.

Let X = 10a + b and Y = 10b + a. X + Y = 11(a + b) = 99, the greatest two-digit number, so a + b = 9. The tens digit a can be 1 to 8 (b = 9 - a must be a non-zero digit), giving 8 possible values of X.

The passage says the merchant learns what is parochial and what is universal only through travel, and that learning fundamental common values is perhaps the greatest gain of travel. Assumptions 1 and 2 follow. Assumption 3 is not: the passage never claims travel experience enables resolving differences among people.

The passage says delicate goods such as justice, love and honour are valid everywhere but variously moulded, and that travel teaches what is parochial and what is universal. Hence when we meet other people while travelling, we learn to differentiate between local values and universal values.

Assumption 1 is wrong: the author asks whether the horrors are the inevitable result of science or whether the fault lies elsewhere - he does not assert inevitability. Assumption 2 is valid: the epigram's easily overlooked truth is the relation between science and mankind - science is what man has made it.

Statement 1 overstates: the passage says nothing about mankind not existing without science. Statement 2 also overstates: it never says science will ultimately determine the destiny of mankind. Hence neither is emphatically conveyed.

1 cubic metre = 1000 litres; 1 metric ton = 1000 kg; and 1 hectare = 10000 square metres. Hence all three statements are correct.

Let the father's and son's present ages be F and S. F - n = S and F = 4(S - n); also F + S = 130. Substituting n = F - S gives F = 4(2S - F), i.e., 5F = 8S. With F + S = 130, F = 80 and S = 50, so the difference of their ages is 30 years.

20%. Take total students as 100. Passed English = 80, so failed English = 20. Passed Hindi = 70, so failed Hindi = 30. Failed both = 15. Failed only one subject = failed English only + failed Hindi only = (20 - 15) + (30 - 15) = 5 + 15 = 20%.

93.75%. Let the number be x. Correct result after multiplying by 4 is 4x. Mistaken result after dividing by 4 is x/4. Difference = 4x - x/4 = 15x/4. Percentage change with respect to the correct result = (15x/4)/(4x) x 100 = 15/16 x 100 = 93.75%.

Let R's salary be 100. Then Q's salary is 80 and P's is 80% of 80, i.e., 64. R's salary exceeds P's by (100 - 64)/64 x 100 = 56.25%.

Let Q invest q; then P invests q + 14000. Profit shares are proportional to capital x time: P : Q = 8(q + 14000) : 10q. Out of the total profit of 2000, P's share is 1200 and Q's is 800, so 8(q + 14000)/10q = 3/2, giving 16(q + 14000) = 30q and q = 16000. Hence P's capital is 16000 + 14000 = Rs. 30,000.

The sequence A _ BCD_ BBCDABC _ DABC_ D consists of four five-letter blocks, each being ABCD with one letter doubled: AABCD, ABBCD, ABCCD, ABCDD. Hence the missing letters are A, A, C and D.

The passage says we now take it for granted that science has a social responsibility - an idea that would not have occurred to Newton or Galileo, and which begins at the industrial revolution. The message is that science must pursue truth but be responsible for social welfare.

The passage shows class-8 children with reading and arithmetic competencies far below curricular expectations, who expect to go on to high school and college rather than agriculture. The central idea is that public policy should ensure that the competencies and achievements of young people are aligned with their expectations.

Assumption 1 is not supported: the passage does not compare the roles of parents and governments. Assumption 2 is not supported: it says nothing about a uniform national curriculum conforming to today's requirements. Hence neither is valid.

1 and 3 only. Distinct prime numbers less than 10 are 2, 3, 5 and 7. Sums of three distinct primes are: 2+3+5=10, 2+3+7=12, 2+5+7=14 and 3+5+7=15. Their unit digits are 0, 2, 4 and 5. So unit digit 0 and 5 are possible, but 9 is not possible.

4. The bottle size must exactly divide both 399 litres and 532 litres. So possible bottle sizes are the positive divisors of gcd(399, 532). Since gcd(399, 532) = 133 = 7 x 19, its divisors are 1, 7, 19 and 133. Hence 4 different bottle sizes are possible.

3. If both 421 and 427 leave remainder 1 on division by the same divisor d, then d must divide 421 - 1 = 420 and 427 - 1 = 426. Hence d must divide gcd(420, 426) = 6. The possible divisors greater than 1 are 2, 3 and 6. Therefore 3 divisors are possible.

9. The number is 30^30 = (3 x 10)^30 = 3^30 x 10^30. The zeros at the end come from 10^30. The rightmost non-zero digit is therefore the unit digit of 3^30. Powers of 3 have unit-digit cycle 3,9,7,1. Since 30 leaves remainder 2 when divided by 4, the unit digit is the second value in the cycle, i.e. 9.

To gain 20% by selling the mixture at the cost price of honey, the honey must be 100/120 = 5/6 of the mixture, so water is 1/6 of the mixture. Water as a percentage of honey = (1/6)/(5/6) x 100 = 20%.

37. The expression is 222^333 + 333^222. Since 222 = 6 x 37 and 333 = 9 x 37, both terms contain 37 as a factor. Hence their sum is divisible by 37. It is not divisible by 2 because 222^333 is even and 333^222 is odd, so the sum is odd. Therefore 37 is the correct divisor among the given options.

Assumption 1 is valid: not every voice on the internet commands the same audience - wealthy private entities can buy a louder voice, so the internet is not inclusive enough. Assumption 2 is valid: when political discourse becomes a matter of outshining one's opponent, the quality of politics suffers. Both are valid.

The passage portrays social media as platforms where capital buys attention and the focus is restricted to content that generates user engagement, regardless of how inflammatory. The inference is that social media are not ideal or moral institutions but products built by companies to make profits.

Assumption 1 is valid: since Indian planning education differs from the West, where systems-approach subjects were absorbed into a curriculum rooted in the social sciences, geography and architecture, India needs a new generation of urban professionals trained in relevant knowledge. Assumption 2 is not: the passage does not say Indian universities have no capacity or potential.

The passage shows Western planning curricula integrating computing, statistics, optimization, social sciences, geography and architecture to produce ingenious planners. The logical inference for India, whose planning education differs, is that the curriculum for urban planning courses should have a diverse and interdisciplinary approach.

8th January, 2023. The daily savings form 1, 3, 5, 7. because each day is Rs. 2 more than the previous day. The sum of the first n odd numbers is n^2. The total saving at the end of day n is therefore n^2. It must also be a perfect cube, so n itself must be a perfect cube. Among the dates given, n = 8 is a cube, and the total is 8^2 = 64 = 4^3. Therefore the date is 8 January 2023.

200. The product is 1^2 x 2^4 x 3^6 x ... x 25^50. Trailing zeroes come from factors of 10, so count factors of 5 because factors of 2 are more than enough. A term n^(2n) contributes 2n x v5(n) factors of 5. For n=5,10,15,20 the contributions are 10,20,30,40. For n=25, v5(25)=2, so contribution is 50 x 2 = 100. Total = 10+20+30+40+100 = 200.

6 hours 45 minutes. Rates are X = 1/6 work/hour, Y = 1/8, Z = 1/8. To minimise time, use X as often as possible but not in consecutive hours. A best sequence is X, Y, X, Z, X, Y for 6 hours: work done = 3/6 + 3/8 = 1/2 + 3/8 = 7/8. Remaining work = 1/8. X can do 1/6 in an hour, so time needed = (1/8)/(1/6) = 3/4 hour = 45 minutes. Total time = 6 hours 45 minutes.

20%. Work is fixed, so men x days is constant. If M men finish the work in 6k days, then required men for 5k days = M x 6k/5k = 6M/5. Increase = 6M/5 - M = M/5, which is 20% of M.

0. Use normal precedence, so multiplication is evaluated before addition and subtraction. One valid choice of operators is 5 - 4 - 3 + 2 x 1. This equals 5 - 4 - 3 + 2 = 0. Since 0 is non-negative and no value can be smaller than 0 among non-negative values, the smallest possible non-negative value is 0.

9. To get 64 identical small cubes, the large cube must be divided as 4 x 4 x 4. That requires 3 cuts along each of the three dimensions. Minimum cuts = 3 + 3 + 3 = 9.

Assumption 1 is not valid: the passage does not say fiscal policies are solely responsible for higher prices. Assumption 2 is not valid either: the passage does not discuss long-term government bonds. Hence neither is valid.

The passage (on fiscal-monetary coordination) implies that central banks cannot bring down inflation without budgetary backing (1) and that the effects of monetary policy depend on the fiscal policies pursued by the government (2). Both inferences are valid.

Assumption 1 is valid: since food is lost throughout the supply chain, the distribution mechanism needs to be reimagined and made effective. Assumption 2 is valid: loss and wastage occur from initial production to final household consumption, making its reduction a responsibility of all citizens. Both are valid.

Statement 2 is valid: wastage results in about 45 per cent land degradation, so land productivity is adversely affected. Statement 3 is valid: the energy spent on wasted food produces about 3.5 billion tonnes of carbon dioxide a year, so reducing wastage lowers the carbon footprint. Statement 1 (solely responsible) and 4 (no post-harvest technologies) are not supported.