UPSC 2015 Prelims Questions with Answers

Of all candidates, men who cleared both stages = 60% x 70% x 80% = 33.6%; women = 40% x 75% x 70% = 21%. So more men cleared than women, overall success is about 54.6% (above 50%), and the men's success rate (56%) is higher than the women's (52.5%). Hence only 'More men cleared the examination than women' is correct.

28. White marbles = 10. White are three less than red, so red = 13. White are five more than green, so green = 5. Total marbles = red + white + green = 13 + 10 + 5 = 28.

A and B are enemies, so one is a fighter and the other a coward. E and F are indifferent to each other, so both are fighters. A and E are not enemies, and since E is a fighter, A must also be a fighter; then B is the coward. B and F are enemies, which confirms F is a fighter. Hence A, E and F are fighters.

A cow costs more than 4 goats and less than 5 goats. With a goat priced between Rs. 600 and Rs. 800, the cow must cost more than 4 x 600 = Rs. 2,400 and less than 5 x 800 = Rs. 4,000. The only statement guaranteed by these bounds is that the cow costs between Rs. 2,400 and Rs. 4,000.

Y, V and W are parallel. X is perpendicular to Y and parallel to Z, so Z is also perpendicular to Y. U is perpendicular to V and W, so V and W are parallel to each other. X is perpendicular to V, so V is parallel to Y; therefore W is also parallel to Y. Hence Y, V and W are parallel.

One of those who can drive a car speaks Tamil. Shabnam speaks Marathi and Anil speaks Tamil. The two drivers are Rekha and David, one woman and one man. Since there must be two Tamil speakers and Anil is already one of them, exactly one among Rekha and David must be the other Tamil speaker. Therefore one of those who can drive speaks Tamil.

21. Let the number of men and women be m and f. Handshakes occur only between opposite sexes, so mf = 24. Factor pairs are (1,24), (2,12), (3,8), and (4,6). Hugs occur within the same sex: C(m,2) + C(f,2). For m=4 and f=6, hugs = C(4,2)+C(6,2)=6+15=21, which matches the option.

2. Arrange the cousins in increasing age. E is fixed as the oldest. The conditions are: F lies between B and D; A is older than B; C is older than D; and A is exactly one year older than C, so C and A must be consecutive in that order. The only valid increasing-age orders are B-F-D-C-A-E and D-F-B-C-A-E. Therefore 2 orders are possible.

From the age order constraints, the increasing-age sequences possible are B-F-D-C-A-E and D-F-B-C-A-E. In both orders F occupies the second position from the youngest, so F is 18 years old. The other options place F at ages inconsistent with both sequences.

48 km/hr. For equal onward and return distances, average speed = 2uv/(u+v). Here u = 40 km/hr and v = 60 km/hr. Average speed = 2 x 40 x 60 / (40 + 60) = 4800/100 = 48 km/hr.

24,000 and 18,000. Let incomes of Peter and Paul be 4x and 3x. Let expenses be 3y and 2y. Since each saves 6,000, 4x - 3y = 6000 and 3x - 2y = 6000. Subtracting gives x - y = 0, so x = y. Then 3x - 2x = 6000, giving x = 6000. Incomes are 4x = 24,000 and 3x = 18,000.

24. Task 2 must go to person 3 or person 4: 2 choices. If task 2 goes to one of them, task 1 cannot go to person 1 or person 2 and also cannot go to the person already assigned task 2. So task 1 has 2 eligible choices. The remaining 3 tasks can be assigned to the remaining 3 persons in 3! = 6 ways. Total ways = 2 x 2 x 6 = 24.

6 : 36 PM. At 6:00, the minute hand is 30 minute-spaces behind the hour hand. To be 3 minute-spaces ahead, it must gain 33 minute-spaces. The minute hand gains 11/12 minute-space per minute over the hour hand, so time required = 33 x 12/11 = 36 minutes. Hence the time is 6:36 PM.

The passage discusses the scale of financial support developing countries need for mitigation and adaptation, which is a matter of intense debate in the UNFCCC negotiations, and notes that the Convention puts the responsibility on developed countries. Essentially it discusses the conflict between developed and developing countries regarding support for mitigation.

The passage says domestic finances of developing countries are likely to fall short of their current and projected needs, so climate change has implications on domestic finances. Multilateral trade capacity is not discussed - only multilateral negotiations on funding.

The passage states the reason squarely: the Convention puts the responsibility for financial support on the developed countries taking into account their contribution to the stock of greenhouse gases in the atmosphere. Per capita income and GDP are not mentioned as grounds.

The intense debate in the UNFCCC negotiations concerns the scale and magnitude of the financial support required by developing countries to enhance their domestic mitigation and adaptation actions - statements 1 and 3. Crop loss is not part of the debate described in the passage.

The tension between the State and the individual remains unresolved because the State has a continuing duty to protect the rights of individuals — the very duty that pulls it in two directions. Options B, C and D refer to law and order, property or liberty alone, none of which captures the rights-protection duty that keeps the conflict alive.

The passage says the right of personal property should unite liberty with equality, and both with cooperation. Option D captures this synthesis: economic justice demands that each person's right to acquire property be reconciled with the rights of others. The other options either absolutize the right or condemn it outright.

The passage lists the causes of persistent inflation - administered price increases, imbalances, imported inflation, speculation - and observes that many of them are outcomes of economic reforms, with vulnerability to international prices rising with trade liberalisation and subsidy reduction pushing up administered prices. The implied message is that economic reforms can often create a high inflation economy.

Swati is slower than Kamala, and Priti is slower than Swati, so Kamala > Swati > Priti. Usha is faster than Kamala, so the complete order is Usha > Kamala > Swati > Priti. The slowest runner is Priti.

Compare the actual amounts, not just the proportions. Family A spends 50% of Rs.20,000 on food = Rs.10,000. Family B spends 10% of Rs.1,00,000 on food = Rs.10,000. The amounts are therefore equal.

At the year 1990, the curve lies between the Rs.10 and Rs.20 gridlines. The graph therefore tells us only that the price was somewhere in the band Rs.10–Rs.20; it does not fix an exact value, and nothing can be said about 1991 from this point alone.

ABCABC = ABC × 1001 (since 1001 × ABC = ABC000 + ABC). Comparing with ABC × DEED, we get DEED = 1001, so D = 1 and E = 0.

Claims of sightings, the possibility of life elsewhere, and the fact that space travel exists do not establish any definite fact about UFOs — none of the statements confirms what UFOs are or where they come from. The only valid conclusion is that nothing definite can be said about the UFOs.

The statements say some men are great and some men are wise. Conclusion I fails because being great and being wise are not stated to be mutually exclusive. Conclusion II fails because the statements do not guarantee that some men are neither great nor wise. Neither conclusion is valid.

G. The source gives corner-adjacency sets: Y-O-B, I-G-Y, B-G-Y and O-V-B. Thus O is adjacent to Y, B and V. On a cube, a face has four adjacent faces and one opposite face; using the given corner sets, G is forced to be the face not adjacent to O among the options. Hence G is opposite O.

Pipe A fills 1/20 of the tank per minute and pipe B fills 1/30 per minute. Together they fill 1/20 + 1/30 = 5/60 = 1/12 of the tank per minute, so the tank fills in 12 minutes.

A's earnings curve lies above B's from 2000 until about 2007, while B leads only from about 2007 to 2010. Over the whole decade the area under A's curve (total earnings) is larger, so on average A earned more than B during the period.

25. Let the number of brown pairs be x and the price of one brown pair be b. One black pair costs 3b. Correct bill = 5(3b) + xb = (15 + x)b. Wrong bill after interchanging quantities = x(3b) + 5b = (3x + 5)b. The question states that the bill increased by 100%, so 3x + 5 = 2(15 + x). Hence x = 25.

7. Without restriction, 2 subjects can be chosen from 5 in C(5,2) = 10 ways. Since Mathematics II can be chosen only with Mathematics I, the invalid choices are Mathematics II with Commerce, Economics or Statistics: 3 invalid pairs. Valid combinations = 10 - 3 = 7.

Choose 1 Principal from the 2 eligible candidates: 2 ways. The remaining 5 candidates are all eligible for the two Vice-Principal posts: C(5,2) = 10 ways. Total combinations = 2 × 10 = 20, which is not among the listed options — hence 'None of the above'.

The passage demands that where discretion has to be used there must be rules and safeguards to prevent misuse, and that government work be conducted within a framework of recognised rules and principles. The logical assumption is that the supremacy of rules and safeguards should prevail over the exclusive discretion of authority.

The passage says formal financial institutions are fundamental for mobilising savings but access to safe instruments is not available to all, especially in rural India. The crucial message is therefore the need to extend this access - to promote financial inclusion - rather than merely to open more banks, raise GDP or raise interest rates.

Statement 1 overstates: the passage says access is not always available to all, not that institutions offer no instruments at all. Statement 2 is supported directly: poor households without access to a formal savings mechanism encourage immediate spending temptations.

The passage says democracy remains phoney while we favour our own caste, community or religion, and that we must respect a man as a man and extend opportunities to those who deserve them. True democracy therefore means providing equal opportunities to all.

The passage traces open defecation through disease, malnourishment, stunting and diminished cognitive potential - that is, damage to the health and capability of people who form India's workforce. The most critical inference is that open defecation reduces the human capital of India's workforce.

The passage notes that portfolio investment from advanced economies into emerging markets has doubled, with implications for Indian policy makers. The implicit risk is that capital inflows can reverse or shock - emerging economies are at risk of shock from advanced economies. The passage does not call such investment bad or urge India to reject it.

The passage links climate change to disrupted crop yields, hunger and malnutrition, hitting the poorest communities worst. Since poverty increases vulnerability to climate impacts and climate impacts deepen poverty, the message is that poverty and climate impacts reinforce each other and food systems must be re-imagined.

Liberty is the maintenance of conditions for the growth of human personality. The quote treats liberty as an atmosphere that allows people to become their best selves. This is positive liberty: conditions for human development, not mere absence of restraint. Option D expresses that idea directly.

The mangroves' leaf litter feeds fungi and bacteria, which feed worms and crustaceans, then small fish, larger fish, birds and crocodiles - a coastal food chain that begins with the mangroves. The logical inference is limited to what this shows: mangroves have a crucial role in some of the coastal food chains, not in all marine ecosystems.

50. Let cars = c and two-wheelers = s. Total wheels = 4c + 2s. Total vehicles = c + s. Given wheels are 100 more than twice the number of vehicles: 4c + 2s = 2(c+s) + 100. This gives 4c + 2s = 2c + 2s + 100, so 2c = 100 and c = 50.

23. Add the language counts: Tamil 6 + Hindi 15 + Gujarati 6 = 27. This count includes each person speaking exactly two languages one extra time, and the person speaking all three languages two extra times. Given exactly two-language speakers = 2 and all-three speaker = 1, actual group size = 27 - 2 - 2 = 23.

40. Failed in English = 62, failed in Mathematics = 52, failed in both = 24. Failed in at least one subject = 62 + 52 - 24 = 90. Therefore students who passed finally = 130 - 90 = 40.

7 : 17. Take each glass capacity as 12 units. First glass has 1/3 milk = 4 units and 8 units water. Second glass has 1/4 milk = 3 units and 9 units water. Total milk = 7 units and total water = 17 units. Ratio of milk to water = 7:17.

25 : 21. A runs the full 500 m. B starts 45 m ahead, so B has to run 455 m to finish, but when A finishes B is still 35 m short. Thus B has run 455 - 35 = 420 m in the same time. Speed ratio A:B = distance ratio = 500:420 = 25:21.

Starting in opposite directions and always turning left (Shahid) and right (Rohit), the two trace symmetric square paths that close back onto each other. Each completes three sides of the square before meeting, so they meet after each has travelled 3 km.

The statements give cauliflower tastier than lady's finger, and lady's finger tastier than cabbage, so cauliflower is tastier than cabbage by transitivity. The statements do not fix peas relative to the other three except that peas are at least as tasty as cabbage.

20%. Use inclusion-exclusion. Percentage reading at least one magazine = 45 + 55 + 40 - 30 - 15 - 25 + 10 = 80%. Therefore percentage reading none = 100 - 80 = 20%.

C has more than what A and D have together. Start with Rs. 100 each. After A pays Rs. 20 to B: A = 80, B = 120. After B pays Rs. 10 to C: B = 110, C = 110. After C gets Rs. 30 from D: C = 140, D = 70. C is richest and D is poorest; B is richer than D. But A + D = 80 + 70 = 150, which is more than C's 140. So the statement that C has more than A and D together is not correct.