CSAT Paper II of the 2015 Preliminary examination, held on 23 August 2015. 80 questions · 200 marks · qualifying at 33%. The questions broke down as Comprehension 32, Logical Reasoning 20, Basic Numeracy 16, Mental Ability 5, Data Interpretation 1.
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.
Which one of the following statements is least essential as a part of the argument in the above passage ?
UPSC's answer: (a) — The passage argues that excluding many from governance is justified to ensure the 'good of society' and the 'viability of the political process.' Option (c) directly supports this by stating that exceptions to universal participation aid systemic efficacy, which aligns with the 'viability'…
Which one of the following statements best sums up the above passage ?
UPSC's answer: (d) — By 2050 the world's population will grow from seven to nine billion and food production may have to double, while climate change, limited arable land and potable water add pressure.
With reference to the above passage, which of the following is the most valid assumption ?
UPSC's answer: (b) — The author says people who believe that cutting defence spending on weapons will bring peace are propagating a ‘false argument’.
Which is the critical inference that can be made from the above passage ?
UPSC's answer: (c) — The passage lists two sets of causes of child deaths: child-care gaps (breastfeeding, immunisation) and maternal-care gaps (no care for 2·6 crore women during pregnancy and after delivery, child marriage, anaemia in young women, poor adolescent hygiene).
With reference to the above passage, which of the following statements is/are true ? 1. Consuming regionally grown food and not depending on long travelled food is a part of eco-friendly behaviour. 2. Food processing industry puts a burden on our natural resources. Select the correct answer using the code given below :
UPSC's answer: (c) — The passage states that long-distance food transportation generates pollution and leads to environmental threats, implying that avoiding such food is eco-friendly, which validates statement 1.
The author says that a thoughtless word hardly ever escapes his tongue or pen. Which one of the following is not a valid reason for this ?
UPSC's answer: (a) — The passage explicitly states that the author's hesitancy in speech has taught him the 'economy of words'. It further explains that he has 'naturally formed the habit of restraining his thoughts' as a direct result of his shyness.
The most appropriate reason for the author to be spared many a mishap is that
UPSC's answer: (a) — The passage explicitly states, 'I can now give myself the certificate that a thoughtless word hardly ever escapes my tongue or pen.' Immediately following this statement, the author concludes, 'I have thus been spared many a mishap and waste of time.' The word 'thus' indicates a direct causal link…
For the author, silence is necessary in order to surmount
UPSC's answer: (d) — The passage explicitly states that 'Proneness to exaggerate, to suppress or modify the truth... is a natural weakness of man.' It immediately follows that 'silence is necessary in order to surmount it,' referring directly to the proneness to exaggerate.
Twelve people form a club. By picking lots, one of them will host a dinner for all once in a month. The number of dinners a particular member has to host in one year is
UPSC's answer: (d) — The problem states that the host is selected by 'picking lots' (random selection) each month, not by a fixed rotation. Since the selection is random, any specific member has a probability of being chosen in any given month, but it is not guaranteed.
An automobile owner reduced his monthly petrol consumption when the prices went up. The price-consumption relationship is as follows : Price (in ₹ per litre) 40 50 60 75 Monthly consumption (in litres) 60 48 40 32 If the price goes up to ₹ 80 per litre, his expected consumption (in litres) will be
UPSC's answer: (a) — Multiply price by consumption for each pair: 40 × 60 = 2,400; 50 × 48 = 2,400; 60 × 40 = 2,400; 75 × 32 = 2,400. The owner always spends ₹ 2,400 a month on petrol, whatever the price. At ₹ 80 per litre he will therefore buy 2,400 ÷ 80 = 30 litres — option (a). Hence option (a).
Consider the following matrix : | 3 | 8 | 10 | 2 | ? | 1 | | 6 | 56 | 90 | 2 | 20 | 0 | What is the missing number at ‘?’ in the matrix ?
UPSC's answer: (a) — In each column, the lower number equals the upper number multiplied by one less than itself: n × (n − 1). Check: 3 × 2 = 6; 8 × 7 = 56; 10 × 9 = 90; 2 × 1 = 2; 1 × 0 = 0. For the fifth column, let the missing upper number be x; then x × (x − 1) = 20.
What is the missing number ‘X’ of the series 7, X, 21, 31, 43 ?
UPSC's answer: (c) — Try X = 13: the series becomes 7, 13, 21, 31, 43. The differences are 6, 8, 10, 12 — rising by 2 each time, a consistent pattern. Hence X = 13, option (c).
In a test, a candidate attempted only 8 questions and secured 50% marks in each of the questions. If he obtained a total of 40% in the test and all questions in the test carried equal marks, how many questions were there in the test ?
UPSC's answer: (b) — Let each question carry 1 mark and let the test have N questions. Marks scored = 8 × 50% = 4. 4 is 40% of the total, so 0.4 × N = 4 and N = 10. Hence option (b).
A father is nine times as old as his son and the mother is eight times as old as the son. The sum of the father's and the mother's age is 51 years. What is the age of the son ?
UPSC's answer: (d) — Let the son's age be represented by the variable 'x'. The father's age is given as nine times the son's age, which is 9x. The mother's age is given as eight times the son's age, which is 8x. The sum of the father's and mother's ages is stated to be 51 years, leading to the equation 9x + 8x = 51.
Four persons A, B, C and D consisting of two married couples are in a group. Both the women are shorter than their respective husbands. A is the tallest among the four. C is taller than B. D is B's brother. In this context, which one of the following statements is not correct ?
UPSC's answer: (c) — D is B's brother, so D is male and B and D are siblings, not a married couple. A is tallest, so A cannot be a wife because her husband would have to be taller; hence A is male. With A and D male, B and C are female; since B and D cannot be a couple, the couples are A-B and C-D.
Consider the following statements : 1. A man had a wife, two sons and two daughters in his family. 2. The daughters were invited to a feast and the male members of the family went out to take part in a picnic. 3. The man's father did not return from his work. Which of the following statements is true ?
UPSC's answer: (b) — The family is the man, his wife, two sons and two daughters. The daughters went to a feast and all male members — the man and both sons — went to a picnic; the man's father had also not returned from work.
Geeta : Naresh has become a better boxer since he started meditation. Radha : Impossible. A boxer's most important asset is his aggressiveness. Radha's statement reflects her belief that
UPSC's answer: (a) — Radha argues that a boxer's most important asset is aggressiveness, implying that any practice reducing this trait would be detrimental to boxing performance.
All good athletes want to win and all athletes who want to win eat a well-balanced diet; therefore all athletes who do not eat a well-balanced diet are bad athletes. The best conclusion from this statement is that
UPSC's answer: (b) — Let G be good athletes, W be those who want to win, and D be those who eat a well-balanced diet. The premise 'All good athletes want to win' translates to G ⊆ W. The premise 'All athletes who want to win eat a well-balanced diet' translates to W ⊆ D.
Which among the following is the most logical and rational assumption that can be made from the above passage ?
UPSC's answer: (a) — The passage explicitly states that richer states have a responsibility to cut carbon emissions and promote clean energy investments due to their higher per capita income and faster growth.
This is a sensitive issue-based story which tries to sensitise the readers about
UPSC's answer: (d) — The story centers on Manak's mother forcing a second marriage to secure a male heir, reflecting a societal obsession with lineage and male offspring.
Which among the following is the most logical and rational inference that can be made from the above passage ?
UPSC's answer: (a) — The passage states the aim of government is to free every man from fear so he can live in security and strengthen his natural right to exist and work. It explicitly rejects ruling by fear or demanding obedience, emphasizing that government should not turn rational beings into beasts or puppets.
Which among the following is the most logical and rational assumption that can be made from the above passage ?
UPSC's answer: (b) — The passage explicitly states that urban services delivery is complex and requires high specialization and professionalism. It identifies that municipal corporations are understaffed and that current recruitment rules fail to factor in necessary technical and managerial competencies.
Which among the following is the most logical corollary to the above passage ?
UPSC's answer: (c) — The passage describes flamingos as social and loyal, performing group mating dances, and gathering chicks into crèches specifically 'for protection' while both parents go to find food. A corollary must be a conclusion that follows directly from these stated facts without overgeneralising.
What is the most logical, rational and crucial message that is implied in the above passage ?
UPSC's answer: (d) — The passage highlights that a vast number of rural citizens are financially and functionally illiterate with little technology experience. It notes that despite the shift to electronic wage payments, over a third of households with bank accounts still receive cash via village leaders.
With reference to the above passage, consider the following statements : 1. In developing countries, a strong institutional framework is the only requirement for human development and policy options. 2. Human development and economic growth are not always positively inter-related. 3. Focusing only on human development should be the goal of economic growth. Which of the above statements is/are correct ?
UPSC's answer: (c) — Statement 1 is incorrect because the passage states that individuals and leaders operate under 'strong institutional, structural and political constraints,' implying that institutional frameworks are just one of several constraints, not the 'only' requirement.
With reference to the above passage, the following assumptions have been made : 1. Higher economic growth is essential to ensure reduction in economic disparity. 2. Environmental degradation is sometimes a consequence of economic growth. Which of the above is/are valid assumption/assumptions ?
UPSC's answer: (b) — The passage explicitly states that an unbalanced emphasis on growth is often associated with negative environmental consequences, which directly supports Assumption 2.
If A runs less fast than B, and B runs as fast but not faster than C; then, as compared to A, C runs
UPSC's answer: (b) — The statement 'A runs less fast than B' establishes the inequality A < B. The statement 'B runs as fast but not faster than C' means B is not slower than C and not faster than C, implying B = C. Substituting C for B in the first inequality gives A < C. Therefore, C runs faster than A.
Each of A, B, C and D has ₹ 100. A pays ₹ 20 to B, who pays ₹ 10 to C, who gets ₹ 30 from D. In this context, which one of the following statements is not correct ?
UPSC's answer: (c) — Each person starts with ₹ 100, so the total money in the system is ₹ 400, and this total remains constant throughout all transactions. A pays ₹ 20 to B, leaving A with ₹ 80 and B with ₹ 120. B pays ₹ 10 to C, leaving B with ₹ 110 and C with ₹ 110.
In a town, 45% population read magazine A, 55% read magazine B, 40% read magazine C, 30% read magazines A and B, 15% read magazines B and C, 25% read magazines A and C; and 10% read all the three magazines. What percentage do not read any magazine ?
UPSC's answer: (c) — Use the Principle of Inclusion-Exclusion to find the percentage of people reading at least one magazine: |A ∪ B ∪ C| = |A| + |B| + |C| - (|A∩B| + |B∩C| + |A∩C|) + |A∩B∩C|. Substitute the given values: 45 + 55 + 40 - (30 + 15 + 25) + 10. Calculate the sum of individual readers: 45 + 55 + 40 = 140.
Examine the following statements : 1. Lady's finger is tastier than cabbage. 2. Cauliflower is tastier than lady's finger. 3. Cabbage is not tastier than peas. The conclusion that can be drawn from these statements is that
UPSC's answer: (d) — Statement 1 tells us Lady's finger is tastier than cabbage, and statement 2 tells us Cauliflower is tastier than Lady's finger. Chaining these two inequalities gives Cauliflower > Lady's finger > Cabbage, so Cauliflower is necessarily tastier than cabbage.
Shahid and Rohit start from the same point in opposite directions. After each 1 km, Shahid always turns left and Rohit always turns right. Which of the following statements is correct ?
UPSC's answer: (b) — Let the starting point be the origin (0,0). Shahid travels North (positive y-axis) and Rohit travels South (negative y-axis) initially. After 1 km, Shahid is at (0,1) and Rohit is at (0,-1). Shahid turns left (West) and Rohit turns right (West).
In a 500 metres race, B starts 45 metres ahead of A, but A wins the race while B is still 35 metres behind. What is the ratio of the speeds of A to B assuming that both start at the same time ?
UPSC's answer: (a) — In a 500 m race, A starts at the 0 m mark and must cover the full 500 m to win. B starts 45 m ahead, so B's starting position is at 45 m, meaning B only needs to cover 500 - 45 = 455 m to reach the finish line.
Two equal glasses of same type are respectively 1/3 and 1/4 full of milk. They are then filled up with water and the contents are mixed in a pot. What is the ratio of milk and water in the pot ?
UPSC's answer: (a) — Let the capacity of each glass be 12 units (LCM of 3 and 4) to simplify calculations. The first glass contains 1/3 of 12 = 4 units of milk and is filled with 8 units of water. The second glass contains 1/4 of 12 = 3 units of milk and is filled with 9 units of water.
Out of 130 students appearing in an examination, 62 failed in English, 52 failed in Mathematics, whereas 24 failed in both English and Mathematics. The number of students who passed finally is
UPSC's answer: (a) — Use the Principle of Inclusion-Exclusion to find the number of students who failed in at least one subject: Failed in English + Failed in Mathematics - Failed in both. Calculate the total failures: 62 + 52 - 24 = 90 students.
In a group of persons travelling in a bus, 6 persons can speak Tamil, 15 can speak Hindi and 6 can speak Gujarati. In that group none can speak any other language. If 2 persons in the group can speak two languages only and one person can speak all the three languages, then how many persons are there in the group ?
UPSC's answer: (c) — Add the language counts: 6 + 15 + 6 = 27. A person who speaks exactly two languages is counted twice, and the person who speaks all three is counted three times. Extra counts = 2 persons × 1 extra + 1 person × 2 extra = 4. Number of persons = 27 − 4 = 23. Hence option (c).
In a parking area, the total number of wheels of all the cars (four-wheelers) and scooters/motorbikes (two-wheelers) is 100 more than twice the number of parked vehicles. The number of cars parked is
UPSC's answer: (c) — Let there be c cars and s two-wheelers. Wheels = 4c + 2s; twice the number of vehicles = 2c + 2s. The difference is 4c + 2s − (2c + 2s) = 2c, and this equals 100. So c = 50. Hence option (c).
The mangroves can shed tons of leaves per acre every year; fungi and bacteria break down this leaf litter and consume it, they then are consumed by tiny worms and crustaceans, which in turn feed small fish, which feed larger fish and birds and crocodiles. Which among the following is the most logical inference of the above statement ?
UPSC's answer: (c) — The passage describes a specific food chain starting with mangrove leaf litter, which is decomposed by fungi and bacteria. This decomposition supports tiny worms and crustaceans, which then feed small fish, larger fish, birds, and crocodiles.
“By liberty I mean the eager maintenance of that atmosphere in which men have the opportunity to be their best selves.” Which one of the following expresses the view implied in the above statement ?
UPSC's answer: (d) — The statement defines liberty as maintaining an 'atmosphere' where individuals can be their 'best selves'. The phrase 'best selves' refers to the full development and realization of one's potential, which is synonymous with the growth of human personality.
Which among the following is the most logical corollary to the above passage ?
UPSC's answer: (b) — The passage explicitly states that climate change disrupts crop yields and increases hunger, particularly affecting the poorest communities. It simultaneously notes that poverty drives climate change because desperate communities resort to unsustainable resource use.
Which among the following is the most rational and critical inference that can be made from the above passage ?
UPSC's answer: (d) — The passage states that the share of portfolio investments from advanced economies in emerging economies has doubled to 12 percent over the past decade.
Which among the following is the most critical inference that can be made from the above passage ?
UPSC's answer: (c) — The passage details a causal chain: open defecation leads to contamination, which causes disease and prevents the absorption of calories and nutrients.
Which one of the following statements best sums up the above passage ?
UPSC's answer: (b) — The passage argues that current democracy is 'phoney' because people favor their own caste, community, or religion over merit. It explicitly states that we must respect individuals as humans and extend opportunities for development to those who deserve them, not just those in our group.
With reference to the above passage, consider the following statements : 1. Indian financial institutions do not offer any financial instruments to rural households to mobilise their savings. 2. Poor households tend to spend their earnings/savings due to lack of access to appropriate financial instruments. Which of the statements given above is/are correct ?
UPSC's answer: (b) — Statement 1 is incorrect because the passage states that access to financial institutions is 'not always available' in rural areas, which implies limited or partial access rather than a complete absence of any financial instruments.
What is the crucial message conveyed in the passage ?
UPSC's answer: (d) — The passage says safe, reliable financial institutions and instruments are fundamental to mobilising savings, but access to them is not always available, especially in rural areas.
Which among the following is the most logical assumption that can be made from the above passage ?
UPSC's answer: (b) — The passage states that discretionary powers to the administration can be done away with and that it is difficult to keep such power within limits. It explicitly argues that where discretion must be used, there must be rules and safeguards to prevent misuse.
A selection is to be made for one post of Principal and two posts of Vice-Principal. Amongst the six candidates called for the interview, only two are eligible for the post of Principal while they all are eligible for the post of Vice-Principal. The number of possible combinations of selectees is
UPSC's answer: (d) — The Principal can be chosen only from the 2 eligible candidates: 2 ways. The two Vice-Principals are then chosen from the remaining 5 candidates: 5C2 = 10 ways. Total selections = 2 × 10 = 20. 20 is not among 4, 12 or 18, so the answer is ‘None of the above’ — option (d). Hence option (d).
A student has to opt for 2 subjects out of 5 subjects for a course, namely, Commerce, Economics, Statistics, Mathematics I and Mathematics II. Mathematics II can be offered only if Mathematics I is also opted. The number of different combinations of two subjects which can be opted is
UPSC's answer: (c) — Without any restriction, 2 subjects can be picked from 5 in 5C2 = 10 ways. Mathematics II is allowed only with Mathematics I, so the pairs Commerce–Maths II, Economics–Maths II and Statistics–Maths II are ruled out.
A person ordered 5 pairs of black socks and some pairs of brown socks. The price of a black pair was thrice that of a brown pair. While preparing the bill, the bill clerk interchanged the number of black and brown pairs by mistake which increased the bill by 100%. What was the number of pairs of brown socks in the original order ?
UPSC's answer: (d) — Let a brown pair cost p, so a black pair costs 3p, and let n brown pairs be ordered. Correct bill = 5 × 3p + n × p = (15 + n)p. With the numbers swapped, the bill = n × 3p + 5 × p = (3n + 5)p. A 100% increase means the wrong bill is double: 3n + 5 = 2(15 + n), so n = 25. Hence option (d).
Two pipes A and B can independently fill a tank completely in 20 and 30 minutes respectively. If both the pipes are opened simultaneously, how much time will they take to fill the tank completely ?
UPSC's answer: (b) — Pipe A fills the tank in 20 minutes, so in one minute it fills 1/20 of the tank. Pipe B fills the tank in 30 minutes, so in one minute it fills 1/30 of the tank. When both pipes are opened simultaneously, the combined rate per minute is 1/20 + 1/30 = 3/60 + 2/60 = 5/60 = 1/12 of the tank.
Each of the six different faces of a cube has been coated with a different colour i.e., V, I, B, G, Y and O. Following information is given : 1. Colours Y, O and B are on adjacent faces. 2. Colours I, G and Y are on adjacent faces. 3. Colours B, G and Y are on adjacent faces. 4. Colours O, V and B are on adjacent faces. Which is the colour of the face opposite to the face coloured with O ?
UPSC's answer: (c) — Y is adjacent to O and B (1), to I and G (2), and to B and G (3). So Y's four neighbours are O, B, I and G, and Y must be opposite V. B is adjacent to Y and O (1), to G (3) and to V (4). So B's neighbours are Y, O, G and V, and B must be opposite I.
Consider the following statements followed by two conclusions : Statements : Some men are great. Some men are wise. Conclusion I : Men are either great or wise. Conclusion II : Some men are neither great nor wise. Which one of the following is correct ?
UPSC's answer: (d) — The statement 'Some men are great' establishes that at least one man is great, but it does not imply that all men are great or that no men are not great. Similarly, 'Some men are wise' confirms the existence of wise men but does not exclude the possibility that some men are neither great nor wise.
Consider the following statements : 1. Some claim to have seen UFOs (Unidentified Flying Objects). 2. Life on other heavenly bodies is considered to be a possibility. 3. Voyage to space is now an established fact. From the above statements, it may be concluded that
UPSC's answer: (d) — Statement 1 notes that some people claim to have seen UFOs, but this is a subjective claim, not a verified fact. Statement 2 states that life on other heavenly bodies is only considered a possibility, not a confirmed reality.
If ABC × DEED = ABCABC; where A, B, C, D and E are different digits, what are the values of D and E ?
UPSC's answer: (c) — ABCABC is the three-digit number ABC written twice, which equals ABC × 1001 (for example, 123123 = 123 × 1001). So ABC × DEED = ABC × 1001, and DEED = 1001. Reading the digits, D = 1 and E = 0 — option (c). Hence option (c).
Usha runs faster than Kamala, Priti runs slower than Swati, Swati runs slower than Kamala. Who is the slowest runner ?
UPSC's answer: (b) — The statement 'Usha runs faster than Kamala' establishes the order: Usha > Kamala. The statement 'Swati runs slower than Kamala' establishes the order: Kamala > Swati. Combining these gives the sequence: Usha > Kamala > Swati.
What is the most logical, rational and crucial message that is implied in the above passage ?
UPSC's answer: (d) — The passage explicitly states that persistent high inflation in India is driven by factors such as administered price increases, demand-supply imbalances, and imported inflation. It identifies a common element among these causes: many are outcomes of economic reforms.
In the light of the argument in the above passage, which one of the following statements is the most convincing explanation ?
UPSC's answer: (d) — The passage explicitly states that no right is absolute, exclusive, or inviolable, establishing that rights must be viewed within a broader social context.
The author's viewpoint can be best summed up in which of the following statements ?
UPSC's answer: (a) — The passage opens by stating that the conflict between man and the State is as old as State history. It explicitly notes that although attempts have been made for centuries to adjust these competing claims, the solution seems to be still far off.
According to the passage, which of the following is/are a matter of intense debate in the multilateral negotiations under UNFCCC regarding the role of developing countries in climate change ? 1. The scale and size of required financial support. 2. The crop loss due to climate change in the developing countries. 3. To enhance the mitigation and adaptation actions in the developing countries. Select the correct answer using the code given below :
UPSC's answer: (c) — The passage explicitly states that 'The scale and magnitude of the financial support required by developing countries' is a matter of intense debate, which corresponds to statement 1.
In this passage, the Convention puts the responsibility for the provision of financial support on the developed countries because of 1. their higher level of per capita incomes. 2. their large quantum of GDP. 3. their large contribution to the stock of GHGs in the atmosphere. Select the correct answer using the code given below :
UPSC's answer: (c) — The passage explicitly states that the Convention puts the responsibility for financial support on developed countries 'taking into account their contribution to the stock of greenhouse gases (GHGs) in the atmosphere.' This directly links the obligation to the historical and current emission levels…
With regards to developing countries, it can be inferred from the passage that climate change is likely to have implications on their 1. domestic finances. 2. capacity for multilateral trade. Select the correct answer using the code given below :
UPSC's answer: (a) — The passage explicitly states that 'domestic finances are likely to fall short of the current and projected needs' of developing countries due to the high costs of climate action.
Which one of the following is essentially discussed in the passage ?
UPSC's answer: (a) — The passage explicitly states that the scale and magnitude of financial support required by developing countries is a 'matter of intense debate' in UNFCCC negotiations.
Between 6 PM and 7 PM the minute hand of a clock will be ahead of the hour hand by 3 minutes at
UPSC's answer: (c) — At 6:00 the hour hand stands at the 6, which is 180° round the dial from the 12, and the minute hand stands at the 12. The minute hand moves 6° a minute and the hour hand 0.5° a minute, so the minute hand gains on it at 5.5° a minute.
There are 5 tasks and 5 persons. Task-1 cannot be assigned to either person-1. or person-2. Task-2 must be assigned to either person-3 or person-4. Every person is to be assigned one task. In how many ways can the assignment be done ?
UPSC's answer: (c) — Task-2 must be assigned to either Person-3 or Person-4, giving 2 possible choices for this specific task. Once Task-2 is assigned, 4 persons remain for the remaining 4 tasks (Task-1, Task-3, Task-4, Task-5). Task-1 cannot be assigned to Person-1 or Person-2.
The monthly incomes of Peter and Paul are in the ratio of 4 : 3. Their expenses are in the ratio of 3 : 2. If each saves ₹ 6,000 at the end of the month, their monthly incomes respectively are (in ₹)
UPSC's answer: (a) — Let the monthly incomes of Peter and Paul be 4x and 3x respectively, based on the given ratio of 4:3. Let their monthly expenses be 3y and 2y respectively, based on the given ratio of 3:2. Since each saves ₹6,000, we form the equations: 4x - 3y = 6,000 and 3x - 2y = 6,000.
Two cities A and B are 360 km apart. A car goes from A to B with a speed of 40 km/hr and returns to A with a speed of 60 km/hr. What is the average speed of the car ?
UPSC's answer: (b) — The total distance traveled is the sum of the distance from A to B and B to A, which is 360 km + 360 km = 720 km. The time taken to travel from A to B is calculated by dividing the distance by the speed: 360 km / 40 km/hr = 9 hours.
Which one of the following is possible ?
UPSC's answer: (b) — The ages are six different whole numbers from 17 to 22, and E is 22. A = C + 1 and C > D, so A and C are near the top; with E at 22, A can be at most 21. Trying A = 21, C = 20 leaves 17, 18 and 19 for B, D and F.
What is the number of logically possible orders of all six cousins in terms of increasing age ?
UPSC's answer: (b) — From the previous item, E = 22, A = 21, C = 20 and F = 18 are fixed, while B and D share 17 and 19 in either order. The two possible orders of increasing age are B, F, D, C, A, E (B = 17, D = 19) and D, F, B, C, A, E (D = 17, B = 19).
In a society it is customary for friends of the same sex to hug and for friends of opposite sex to shake hands when they meet. A group of friends met in a party and there were 24 handshakes. Which one among the following numbers indicates the possible number of hugs ?
UPSC's answer: (c) — Let there be m men and w women. Handshakes happen only between a man and a woman, so m × w = 24. Hugs happen between two people of the same sex, so hugs = m(m − 1)/2 + w(w − 1)/2. Possible (m, w): (1, 24) gives 276 hugs; (2, 12) gives 67; (3, 8) gives 31; (4, 6) gives 6 + 15 = 21.
Two men, Anil and David, and two women, Shabnam and Rekha are in a sales group. Only two speak Tamil. The other two speak Marathi. Only one man and one woman can drive a car. Shabnam speaks Marathi. Anil speaks Tamil. Both Rekha and David can drive. Which of the following statements is true ?
UPSC's answer: (d) — Only one man and one woman can drive, and Rekha and David can drive, so the two drivers are David and Rekha; Anil and Shabnam do not drive. Anil speaks Tamil and Shabnam speaks Marathi. Since exactly two speak each language, one of David and Rekha speaks Tamil and the other Marathi.
In a plane, line X is perpendicular to line Y and parallel to line Z; line U is perpendicular to both lines V and W; line X is perpendicular to line V. Which one of the following statements is correct ?
UPSC's answer: (d) — Since X is perpendicular to Y and parallel to Z, Z is also perpendicular to Y. Since U is perpendicular to both V and W, V and W are parallel to each other. Since X is perpendicular to V and V is parallel to W, X is perpendicular to W; since X is parallel to Z, Z is perpendicular to W.
A cow costs more than 4 goats but less than 5 goats. If a goat costs between ₹ 600 and ₹ 800, which of the following is a most valid conclusion ?
UPSC's answer: (d) — A goat costs between ₹ 600 and ₹ 800, and a cow costs more than 4 goats but less than 5 goats. Lowest possible cow price: just over 4 × 600 = ₹ 2,400. Highest: just under 5 × 800 = ₹ 4,000. So all we can say for certain is that a cow costs between ₹ 2,400 and ₹ 4,000 — option (d). Hence option (d).
A society consists of only two types of people — fighters and cowards. Two cowards are always friends. A fighter and a coward are always enemies. Fighters are indifferent to one another. If A and B are enemies, C and D are friends, E and F are indifferent to each other, A and E are not enemies, while B and F are enemies. Which of the following statements is correct ?
UPSC's answer: (b) — Since C and D are friends, and only two cowards are always friends, both C and D must be cowards. Since E and F are indifferent to each other, and only fighters are indifferent to one another, both E and F must be fighters.
In a box of marbles, there are three less white marbles than the red ones and five more white marbles than the green ones. If there are a total of 10 white marbles, how many marbles are there in the box ?
UPSC's answer: (b) — Let the number of white marbles be W, red marbles be R, and green marbles be G. The problem states there are 10 white marbles, so W = 10. There are three less white marbles than red ones, meaning W = R - 3, so R = W + 3 = 10 + 3 = 13.
Candidates in a competitive examination consisted of 60% men and 40% women. 70% men and 75% women cleared the qualifying test and entered the final test where 80% men and 70% women were successful. Which of the following statements is correct ?
UPSC's answer: (c) — Assume a total of 100 candidates: 60 men and 40 women. Men who cleared the final test: 60 * 70% * 80% = 33.6 men. Women who cleared the final test: 40 * 75% * 70% = 21 women. Comparing the final successful candidates, 33.6 men is greater than 21 women.
Question paper and answer key: Union Public Service Commission. Explanations: UPSC Answer Check. Practise this paper with a timer →
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