UPSC 2017 CSAT PYQs with Answers

342. Pages 1 to 9 contribute 9 digits. Pages 10 to 99 contribute 90 x 2 = 180 digits. Pages 100 to 150 contribute 51 x 3 = 153 digits. Total digits printed = 9 + 180 + 153 = 342.

Let the number be 10a+b. (10a+b) - (10b+a) = 9(a-b) = 27 gives a-b = 3. The numbers 30, 41, 52, 63, 74, 85 and 96 (7 numbers) satisfy this, so none of the options is correct.

With G-C closed, the only route from H to C is H-G-B-F-D-E-C, which passes through G, B, F, D and E but not A. Hence A need not be passed through.

List all routes from F without visiting any station twice: F-D-E-A; F-D-E-C-A; F-D-E-G-C-A; and F-D-H-G-C-A. That gives 4 different ways.

From C the only outgoing passage is C-A, and from A every onward route proceeds through E (A-E). So every route from C to H must pass through E; for example, C-A-E-D-H or C-A-E-G-B-F-D-H.

4 m. Treat the two walls and the ceiling as three mutually perpendicular planes meeting at P. The fly is 1 m from one wall, 8 m from the other wall and x m from the ceiling. Its distance from P is therefore sqrt(1^2 + 8^2 + x^2) = 9. So 1 + 64 + x^2 = 81, giving x^2 = 16 and x = 4 m.

42,000. Let incomes be 4x and 3x, and expenses be 3y and 2y. Savings are equal at 6,000: 4x - 3y = 6000 and 3x - 2y = 6000. Subtracting gives x = y. Then x = 6000. Total income = 4x + 3x = 7x = 42,000.

45. Let the two-digit number be 10a+b and its reversal be 10b+a. The difference between them is 9(a-b), and the larger number divided by the smaller can have the largest remainder by direct checking of valid digit pairs. The maximum occurs for 94 divided by 49: 94 = 49 x 1 + 45. Therefore the largest possible remainder is 45.

Count the subjects each teacher teaches. A teaches Hindi, English and Mathematics (3). B teaches Hindi, English, Geography, History and French (5). C teaches English and Geography (2). D teaches Mathematics and Hindi (2). E teaches History and French (2). Hence B teaches the maximum number of subjects.

C is from Delhi (Sociology), D from Shillong, F from Srinagar (Commerce), G from Chennai (Statistics) and B from Kanpur (Geography). A, who is specialized in Economics, does not belong to Hyderabad, so A is from Mumbai and the remaining lecturer E belongs to Hyderabad.

A is specialized in Economics. A does not belong to Hyderabad, and the other cities are already taken - Delhi (C), Shillong (D), Kanpur (B), Srinagar (F) and Chennai (G). Hence the Economics lecturer A belongs to Mumbai.

Economics is A, Commerce is F, Sociology is C and Statistics is G. B is specialized in neither History nor Mathematics, so B must be the Geography specialist (from Kanpur). Hence B is specialized in Geography.

0.80 inch. First four days' total rainfall = 4 x 0.40 = 1.60 inches. Six days' total rainfall = 6 x 0.50 = 3.00 inches. Last two days' total = 3.00 - 1.60 = 1.40 inches. Their ratio is 4:3, so the fifth day = 4/7 x 1.40 = 0.80 inch.

The statement says that every man who is to live under a government ought first to put himself under it by his own consent, and that even the poorest man is not bound to a government in which he has had no voice. This argues for rule according to the consent of the governed.

The analogy treats the States as pearls and the Centre as the thread that holds them together in a necklace; if the thread snaps, the pearls scatter. The view that corroborates this statement is that a strong Centre is a binding force for national integrity.

Despite record production and food stocks, undernourishment persists and food absorbs a large share of household spending. The corollary: improving the farm-to-fork value chain is necessary to reduce poverty and malnutrition.

To move into high-tech, capital-intensive manufacturing and raise its share to 25% of GDP, India should push public investment and encourage private investment in R&D, technology upgradation and skill development.

Ecoagricultural farms suffered less hurricane damage and boosted incomes while increasing biodiversity. Such practices can increase farm output and reduce vulnerability to disasters.

The passage argues that dependence on agriculture must shrink and productive jobs outside agriculture must grow, even while improving agricultural productivity.

The passage says an AQI is useful when pollution is normally low, but in many large Indian cities levels remain above standards for much of the year, so an index stuck in the red day after day gets ignored. The logical inference is that the air quality index is not helpful to the residents of many of our large cities.

4. Compare the codes. In 256 and 254, the common words are colour and chalk, so the common digits 2 and 5 represent colour/chalk in some order. In 589, the common word with 256 is colour, so 5 represents colour. Therefore 2 represents chalk. In 254, after removing 2 for chalk and 5 for colour, the remaining digit 4 represents white.

Fixing E at the 7th position from the left, A is 6th to the left of E, so A is 1st and F is 6th with G 5th (F is to the immediate right of G). H is sixth to the right of C, placing C at 2 and H at 8. B cannot neighbour G, so B is 3rd, and D is 4th. Hence G is to the immediate right of D.

8. A 4 cm cube cut into 1 cm cubes gives a 4 x 4 x 4 arrangement. Cubes with no painted face are the interior cubes, obtained after removing the outer layer on all sides: (4-2)^3 = 2^3 = 8.

3. Treat the two boys as occupying two positions first: B _ B creates three available gaps around/between boys. To keep the two girls non-adjacent, choose two of these three gaps. Number of arrangements = C(3,2) = 3. This matches the option when boys and girls are treated by category, as UPSC intends in this item.

16. To guarantee at least one ball of each colour, consider the worst case. The bag has 8 green, 7 white and 5 red. The largest number that can be drawn while still missing one colour is drawing all green and all white: 8 + 7 = 15. The next draw must be red. Therefore minimum required = 16.

A and E are sons of F; A's son is B; D is the mother of one boy (B) and one girl (C). With three males (A, E, B) and one married couple, A is the husband of D.

P = 3Q and P + Q = 4R, so 4Q = 4R, i.e. R = Q. Earnings ratio P:Q:R = 3:1:1.

Let last year's age be a square and next year's age be a cube, so cube - square = 2. This holds for 27 - 25 = 2, so Mr. X is 26 years old this year. The next cube after 27 is 64, so he must wait 64 - 26 = 38 years for his age to become a cube again.

For unimodal data, Mean < Median < Mode indicates a distribution skewed to the left (negatively skewed).

90. The numbers between 99 and 1000 with units digit 8 are 108, 118, 128, ..., 998. This arithmetic sequence has first term 108, last term 998 and common difference 10. Count = ((998-108)/10)+1 = 90.

If some colours are not pleasant (statement 4), the universal claim that all colours are pleasant cannot be true, so statement 1 is definitely false. Statement 3 need not hold because some colours could still be pleasant, and statement 2 need not hold either. Hence only 1 is false.

4. Check 3-digit numbers with all digits different such that both the number and its reverse are divisible by 7. The valid numbers are 168, 259, 861 and 952. Their reverses, 861, 952, 168 and 259, are also divisible by 7. Hence there are 4 such numbers.

Biopesticides are not hazardous to human health (statement 1 correct) and they help maintain the biodiversity of an ecosystem (statement 3 correct). They are generally NOT persistent in the environment (statement 2 incorrect). Hence 1 and 3 only.

Assumption 2 is valid: the passage contrasts synthetic pesticides that persist in the environment and harm predators with botanical pesticides that decompose easily and maintain biological diversity, so sustainable agriculture aims at minimal ecological imbalance. Assumption 1 (never use synthetic pesticides) and 3 (botanical are more effective) are not stated.

The passage says there is no consensus on the definition of climate refugees and there are gaps in understanding how climate change drives migration. The relation between climate change and migration is not yet properly understood.

The passage shows innovation and R&D mitigating inequality and helping the poor. The assumption that inclusive innovation and R&D can help create an egalitarian society is valid.

The middle-income trap means incomes stop growing well short of developed-country levels. The inference is that once a country reaches the middle-income stage, it runs the risk of falling productivity which leads to stagnant incomes.

The digital now structures who we are, how we connect and how we live. Speaking of digital technologies is speaking of our life and living.

Devolution succeeds only with political legitimacy, i.e. free expression of the people's will and active grassroots participation. That requires democracy at the lower level.

Disruption of traditional institutions may push some people toward old loyalties and others toward new groups. Political development is not a unilinear process; it involves both growth and decay.

Neha > Randhir and Sonal > Shankar, but Sonal can still be greater than Neha (Shankar alone may exceed Neha). Data are inadequate.

240 km. The freight train has a 2-hour head start at 40 km/hr, so its lead is 80 km. The express train gains at 60 - 40 = 20 km/hr. Time to catch up = 80/20 = 4 hours after the express starts. Distance from Delhi = 60 x 4 = 240 km.

36. With 4 horizontal and 4 vertical lines, choose any 2 horizontal lines and any 2 vertical lines to form a rectangle. Number of rectangles = C(4,2) x C(4,2) = 6 x 6 = 36. Since the lines are equally spaced, squares are included within this rectangle count; the maximum number of rectangles and squares formed is 36.

One-third of the 50% water mixture is mixed with an equal quantity of pure milk. Water content = (1/3 x 50%) / (1/3 + 1/3) = (1/6)/(2/3) = 25%.

B, C and F. Start with 10 cards each. F borrows 2 from A: A=8, F=12. F gives 5 to C: F=7, C=15. C gives 3 to B: C=12, B=13. B gives 6 to D: B=7, D=16. D passes those 6 to E: D=10, E=16. D and E together have 26 cards. A+B+F = 8+7+7 = 22; B+C+F = 7+12+7 = 26. Hence B, C and F equal D and E together.

47. Thirteen consecutive odd numbers form an arithmetic progression with common difference 2. The mean of the first five is the middle of those five, i.e. the 3rd number, so the 3rd number is 39. The 7th number, which is the middle of all thirteen numbers, is 39 + 4 x 2 = 47. Hence the mean of all thirteen numbers is 47.

The statement says morning walk is good for health. Conclusion 1 reverses it - not all healthy people necessarily walk. Conclusion 2 captures the statement's thrust that walking is important for maintaining good health, and is the official valid conclusion.

The clock strikes 5 times in 12 seconds, i.e. 12/5 = 2.4 seconds per strike. Ten strikes therefore take 10 x 2.4 = 24 seconds.

240. Households earning more than 1,00,000 are 22%. Households earning more than 2,00,000 are 6%. Therefore households earning between 1,00,000 and 2,00,000 are 16% of total households. Households between 30,000 and 1,00,000 are 990. Also, less than 30,000 = 12%, between 30,000 and 1,00,000 = 66%, between 1,00,000 and 2,00,000 = 16%, and above 2,00,000 = 6%. Thus 66% = 990, total households = 1500, and 16% of 1500 = 240.

The watches drift apart by 4 minutes every 24 hours. For them to show identical time again the drift must complete a 12-hour or 24-hour cycle, which takes 180 or 360 days. None of the given options is correct.

Q - P = 0.1A - 0.15B = 0.1(A - 1.5B). Since A > B alone does not fix the sign of (A - 1.5B), nothing can be concluded with certainty.

Bank employees are Vimala, Kamla and Nirmala (Amala and Komala are unemployed). Tennis players include Komala and Nirmala. Hence Nirmala is both a tennis player and a bank employee.

50 kg. Total weight of 9 persons = 9 x 50 = 450 kg. First 5 persons weigh 5 x 45 = 225 kg. Last 5 persons weigh 5 x 55 = 275 kg. Adding these two totals counts the 5th person twice, so 225 + 275 = 450 + weight of 5th person. Therefore the 5th person's weight is 50 kg.

Assumption 1 is not valid: the passage says studying famous battles reveals the qualities of winners and deficiencies of losers that recur through the centuries, not that it helps understand modern warfare. Assumption 2 is valid: the passage explicitly offers such study to those who lead or aspire to leadership.

Statement 1 is not valid: the passage never says people always see leisure as a gift to be used for acquiring more possessions. Statement 2 is valid: the creative use of leisure by a minority has been the mainspring of all human progress beyond the primitive level.

The passage says a dictator often reaches power "through the unhappy state of his country". It suggests that despair in a country sometimes leads to dictatorship.

The passage calls refraining from voting "implied anarchy" and a refusal of political responsibility. It relates to the duty to vote.

In a mature democracy the will of the sovereign law-making body and the organized will of the people seldom conflict, so force is narrowed to a marginal phenomenon in the exercise of sovereignty.

Rousseau's General Will is the collective good, distinct from the sum of private wills (the "will of all").

The passage calls for hard work to redeem the pledge, equality for all citizens and rejection of communalism. The challenge thrown to the public is hard work, brotherhood and national unity.

Let Gopal's cost price be Rs. 100. He sells to Ram at Rs. 110, a 10% profit. Ram sells the phone back at a 10% loss on Rs. 110, i.e., for Rs. 99. Gopal therefore recovers the phone for Rs. 99 against his original cost of Rs. 100, so his net position is a gain of 1%.

P + R means P is the son of R, and R - Q means R is the wife of Q. So P is the son of R, and R is Q's wife; therefore Q is the father of P.

52 - 15 = 37 students appear in the merit list. Ramesh is 22nd from the top, so from the bottom he is 37 - 22 + 1 = 16th.

Rights aim at both individual and social good. The statement defines rights as conditions of social well-being needed for the citizen's development. It therefore combines individual development with social good. Options A and B isolate only one side; D removes the social-wellbeing element. Option C keeps both individual and social dimensions.

For a spider that climbs c cm and slips s cm per chance, the pillar is topped on the 40th chance without a slip: height = 39 x (c - s) + c. A: 39 x 5 + 6 = 201 cm. B: 39 x 4 + 7 = 163 cm. C: 39 x 4.5 + 6.5 = 182 cm. The shortest pillar is Y, at 163 cm.

Conclusion II follows: the statement says one has to keep practising to improve in music, which implies that even a person whose voice is not naturally good can keep practising. Conclusion I (natural gifts need nurturing) is not what the statement conveys, so only II follows.

A = (B+D)/2 and A+C = B+D give C = A. Since A+B > C+D = A+D, we get B > D; and B+D = 2A with B > D gives B > A. Hence B has the highest income.

Chemistry is conducted exactly after two tests are held, so Chemistry is the third test. Physics is held before the test conducted after Biology, so Biology must be the second test and Physics the first. The order is Physics, Biology, Chemistry, Mathematics; hence Mathematics is the last test.

Each year two-thirds of the population remains (one-third migrates). After six years, the leftover fraction is (2/3)^6 = 64/729 of the original population.

In the shortest month of 28 days there are 4 Sundays and 2 holidays on the second and fourth Saturdays, i.e. 6 holidays. Minimum working days = 28 - 6 = 22.

The passage refers to supporters of party X who knew Z and supported his campaign strategy, so statement 1 (some supporters of party X knew Z) follows from the information. Statement 2, about supporters who opposed Z's strategy, is not supported by the passage, and statement 3 is contradicted by it. Hence statements 2 and 3 are not correct.

The information says that some supporters of 'party X' who knew Z and supported his campaign strategy did not agree for the alliance, but some of them had friends in 'party Y'. This directly implies that there is at least one supporter of 'party Y' who knew some supporters of 'party X' as a friend. The other options are not forced by the given information.

The passage says habits "simplify the mechanism of life" and enable automatic functioning. Habits make it easier for us to live.

The passage insists that freedom from the obligation to work is unnatural - humanity would perish without work - but ends by asking how much leisure we can afford to allow ourselves. The main idea is that there should be a balance between work and leisure.

India has a youth surplus and a vast labour force, but 93% works in the unorganized sector. Labour reforms are required to make optimum, productive use of this labour force.

While GDP grew 50%, inclusive wealth grew only 6% and natural capital declined 30%. The passage implies that GDP-only growth is neither desirable nor sustainable.

The passage identifies ideas of purity/pollution and fear of pit-emptying as the reasons people avoid toilets. The message: people must perceive toilet use and pit-emptying as clean, not polluting.

The melting of Arctic sea ice undermines the food web "atop which stand polar bears". The crucial message: climate change poses a threat to the survival of polar bears.

The passage praises the person who resolves firmly and executes with inflexible perseverance. The keynote is to be resolute and achievement-oriented.

Climate change reduces resources, and competition over diminishing resources leads to political or even violent conflict. Environmental issues therefore contribute to resource stresses and political conflict.