CSAT Paper II of the 2019 Preliminary examination, held on 2 June 2019. 80 questions · 200 marks · qualifying at 33%. The questions broke down as Comprehension 35, Basic Numeracy 22, Mental Ability 13, Logical Reasoning 8, 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.
What is the main idea that we can infer from the passage ?
UPSC's answer: (d) — The passage states that historical injustices, such as untouchability, 'tend to resist repair' due to deep historical roots and complex structural overlaps. It explains that injustice constitutes economic structures, ideologies, and modes of representation, making the category complex.
On the basis of the above passage, the following assumptions have been made : 1. Removal of economic discrimination leads to removal of social discrimination. 2. Democratic polity is the best way to repair historical wrongs. Which of the above assumptions is/are valid ?
UPSC's answer: (d) — The passage states that historical injustice involves overlapping wrongs like economic deprivation and social discrimination, but notes that discrimination tends to acquire 'partial autonomy' from other wrongs.
On the basis of the above passage, the following assumptions have been made : 1. A society without well educated people cannot be transformed into a modern society. 2. Without acquiring culture, a person's education is not complete. Which of the above assumptions is/are valid ?
UPSC's answer: (b) — The passage states that education plays a 'great transformatory role' in life, implying that education is a key driver of transformation, but it does not explicitly state that a society *cannot* be transformed without well-educated people, making Assumption 1 too strong and not directly supported.
On the basis of the above passage, the following assumptions have been made : 1. Large scale soil erosion is a major reason for widespread food insecurity in the world. 2. Soil erosion is mainly anthropogenic. 3. Sustainable management of soils helps in combating climate change. Which of the above assumptions is/are valid ?
UPSC's answer: (b) — Assumption 1 is invalid because the passage states soil is where food grows and erosion is alarming for food producers, but it does not explicitly claim that erosion is a 'major reason' for 'widespread food insecurity' globally.
On the basis of the above passage, the following assumptions have been made : 1. Economic power is the only reason for the existence of inequality in a society. 2. Inequality of different kinds, income, wealth, etc. reinforces power. 3. Economic power can be analysed more through its effects than by direct empirical methods. Which of the above assumptions is/are valid ?
UPSC's answer: (b) — Assumption 1 is invalid because the passage states that economic power is the 'organising principle' of inequality, not the 'only reason' for its existence, which is an absolute claim not supported by the text.
Which one of the following is the most logical and rational inference that can be made from the above passage ?
UPSC's answer: (a) — The passage states that climate change has mixed effects, with some farmlands benefiting from warming while others suffer from pests, droughts, or flooding.
Which one of the following is the most logical, scientific and rational inference that can be made from the above passage ?
UPSC's answer: (d) — The passage highlights that the hand of a man, mole, horse, porpoise, and bat are all constructed on the same underlying pattern of bones (five fingers, wrist bones, arm bones).
Based on the above passage, the following assumptions have been made : 1. Global warming has a bearing on the planet's biological evolution. 2. Separation of land masses causes the release of huge quantities of carbon into the atmosphere. 3. Increased warming of Earth's atmosphere can change the composition of its flora and fauna. 4. The present man-made global warming will finally lead to conditions similar to those which happened 56 million years ago. Which of the assumptions given above are valid ?
UPSC's answer: (c) — Assumption 1 is valid because the passage states that the rapid warming during the PETM led to drastic changes in life, indicating a direct link between global warming and biological evolution.
The number of times the digit 5 will appear while writing the integers from 1 to 1000 is
UPSC's answer: (c) — To count the occurrences of the digit 5 in numbers from 1 to 1000, we analyze each place value (units, tens, hundreds) separately. In the units place, the digit 5 appears once in every block of 10 numbers (e.g., 5, 15, 25...), resulting in 100 occurrences in the range 1-999.
A solid cube is painted yellow, blue and black such that opposite faces are of same colour. The cube is then cut into 36 cubes of two different sizes such that 32 cubes are small and the other four cubes are big. None of the faces of the bigger cubes is painted blue. How many cubes have only one face painted ?
UPSC's answer: (c) — The volumes fix the cut: 4 big cubes and 32 small cubes can only come from a cube of side 4 units, cut into 4 big cubes of side 2 (4 × 8 = 32 unit volumes) and 32 small cubes of side 1 (32 unit volumes), 64 in all. The big cubes have no blue face, so they cannot touch the two opposite blue faces.
A and B are two heavy steel blocks. If B is placed on the top of A, the weight increases by 60%. How much weight will reduce with respect to the total weight of A and B, if B is removed from the top of A ?
UPSC's answer: (d) — Let A weigh 100 units. Placing B on A raises the weight by 60%, so B weighs 60 units and A + B = 160 units. Removing B takes away 60 units out of the combined 160. Reduction = 60 ÷ 160 × 100 = 37·5%, option (d).
Consider the following Statements and Conclusions : Statements : 1. Some rats are cats. 2. Some cats are dogs. 3. No dog is a cow. Conclusions : I. No cow is a cat. II. No dog is a rat. III. Some cats are rats. Which of the above conclusions is/are drawn from the statements ?
UPSC's answer: (c) — Statement 1 states 'Some rats are cats', which logically implies 'Some cats are rats' (converse), making Conclusion III valid.
The number of parallelograms that can be formed from a set of four parallel lines intersecting another set of four parallel lines, is
UPSC's answer: (d) — A parallelogram is formed by selecting exactly two lines from the first set of four parallel lines and exactly two lines from the second set of four parallel lines. The number of ways to choose 2 lines from the first set of 4 is calculated using the combination formula C(4, 2) = 4! / (2! * 2!) = 6.
In a school every student is assigned a unique identification number. A student is a football player if and only if the identification number is divisible by 4, whereas a student is a cricketer if and only if the identification number is divisible by 6. If every number from 1 to 100 is assigned to a student, then how many of them play cricket as well as football ?
UPSC's answer: (b) — A student plays both cricket and football if their identification number is divisible by both 4 and 6. The least common multiple (LCM) of 4 and 6 is 12. Therefore, we need to count how many numbers from 1 to 100 are divisible by 12.
When a runner was crossing the 12 km mark, she was informed that she had completed only 80% of the race. How many kilometres was the runner supposed to run in this event ?
UPSC's answer: (b) — The problem states that the runner has covered 12 km, which represents 80% of the total race distance. Let the total distance of the race be denoted by 'D' kilometres. According to the given information, 80% of D is equal to 12 km, which can be written as the equation: 0.80 * D = 12.
Raju has ₹ 9000 with him and he wants to buy a mobile handset; but he finds that he has only 75% of the amount required to buy the handset. Therefore, he borrows ₹ 2000 from a friend. Then
UPSC's answer: (a) — Raju has ₹9000, which represents 75% of the total cost of the mobile handset. To find the full cost, divide ₹9000 by 0.75, which equals ₹12,000. Raju borrows ₹2,000, bringing his total available funds to ₹9,000 + ₹2,000 = ₹11,000. The required amount is ₹12,000, but Raju only has ₹11,000.
In 2002, Meenu's age was one-third of the age of Meera, whereas in 2010, Meenu's age was half the age of Meera. What is Meenu's year of birth ?
UPSC's answer: (b) — Let Meenu be x years old in 2002; Meera is then 3x years old. In 2010 both are 8 years older, and Meenu is half Meera's age: x + 8 = ½ (3x + 8). So 2x + 16 = 3x + 8, giving x = 8. Meenu was 8 in 2002, so she was born in 2002 − 8 = 1994, option (b).
Rakesh and Rajesh together bought 10 balls and 10 rackets. Rakesh spent ₹ 1300 and Rajesh spent ₹ 1500. If each racket costs three times a ball does, then what is the price of a racket ?
UPSC's answer: (c) — Total amount spent by Rakesh and Rajesh is ₹1300 + ₹1500 = ₹2800. They bought a total of 10 balls and 10 rackets. Let the price of one ball be x, so the price of one racket is 3x. The total cost equation is 10x + 10(3x) = 2800. Simplifying gives 10x + 30x = 2800, which means 40x = 2800.
In a conference, out of a total 100 participants, 70 are Indians. If 60 of the total participants are vegetarian, then which of the following statements is/are correct ? 1. At least 30 Indian participants are vegetarian. 2. At least 10 Indian participants are non-vegetarian. Select the correct answer using the codes given below :
UPSC's answer: (c) — Total participants = 100, Indians = 70, Non-Indians = 30. Total vegetarians = 60, Total non-vegetarians = 40. To find the minimum number of Indian vegetarians, assume the maximum number of Non-Indian vegetarians. Since there are only 30 Non-Indians, at most 30 can be vegetarians.
Which one of the following statements is the most logical and rational inference that can be made from the above passage ?
UPSC's answer: (d) — The passage states that low-end IoT devices are cheap commodity items where addressing security would add to the cost, implying security is often neglected or insufficient in this class of devices.
Which one of the following is the most logical and rational corollary to the above passage ?
UPSC's answer: (b) — The passage argues that global trade negotiations are attempting to 'colonize' the digital sector by extracting Big Data from developing countries. It highlights that this data is converted into digital intelligence in developed countries, which then controls sectors and extracts monopoly rents.
Which of the following is most definitively implied by the above passage ?
UPSC's answer: (a) — The passage states that global trade negotiations are targeting the digital area to 'pre-emptively colonise' it, indicating a strategic race for control over this sector.
What is the most logical and rational corollary to the above passage ?
UPSC's answer: (a) — The passage establishes that rural poor and small farmers contribute little to climate change but face severe impacts like extreme weather and water scarcity.
The above passage implies that 1. There is a potential problem of food insecurity in India. 2. India will have to strengthen its disaster management capabilities. Which of the above assumptions is/are valid ?
UPSC's answer: (c) — The passage states that small-holder farmers in India produce 41 percent of the country's food grains, which are critical for local and national food security.
On the basis of the above passage, the following assumptions have been made : 1. Governments and companies need to be adequately prepared to face the climate change. 2. Extreme weather events will reduce the economic growth of governments and companies in future. 3. Ignoring climate change is a huge risk for investors. Which of the above assumptions is/are valid ?
UPSC's answer: (c) — Assumption 1 is valid because the passage states that governments will make efforts to deal with climate change and companies will face higher taxes and regulatory burdens, implying a need for preparation.
With reference to the above passage, the following assumptions have been made : 1. Making equality of opportunity a reality is the fundamental goal of the Indian education system. 2. The present Indian school system is unable to provide egalitarian education. 3. Abolition of private schools and establishment of more government schools is the only way to ensure egalitarian education. Which of the above assumptions is/are valid ?
UPSC's answer: (b) — Assumption 1 is invalid because the passage states that the idea of an egalitarian system with equality of opportunity is 'outside the space that private school principals inhabit,' implying it is not currently the fundamental goal or reality of the system, but rather an ideal being imposed.
Which one of the following is the most logical, rational and crucial message conveyed by the above passage ?
UPSC's answer: (b) — The passage highlights that TB is exacerbated by poverty, lack of nutrition, and poor housing, which are social determinants beyond medical scope. It explicitly states that stigma, lack of counselling, expensive treatment, and side-effects demotivate patients, leading to treatment discontinuation.
A five-storeyed building with floors from I to V is painted using four different colours and only one colour is used to paint a floor. Consider the following statements : 1. The middle three floors are painted in different colours. 2. The second (II) and the fourth (IV) floors are painted in different colours. 3. The first (I) and the fifth (V) floors are painted red. To ensure that any two consecutive floors have different colours
UPSC's answer: (b) — Five floors are painted with four different colours, one colour per floor, so all four colours are used and exactly one colour appears on two floors. Statement 3 says floors I and V are both red, so red is the repeated colour.
P, Q and R are three towns. The distance between P and Q is 60 km, whereas the distance between P and R is 80 km. Q is in the West of P and R is in the South of P. What is the distance between Q and R ?
UPSC's answer: (d) — Q is due west of P and R is due south of P, so the angle QPR is a right angle. QR² = PQ² + PR² = 60² + 80² = 3600 + 6400 = 10000. QR = √10000 = 100 km, option (d).
All members of a club went to Mumbai and stayed in a hotel. On the first day, 80% went for shopping and 50% went for sightseeing, whereas 10% took rest in the hotel. Which of the following conclusion(s) can be drawn from the above data ? 1. 40% members went for shopping as well as sightseeing. 2. 20% members went for only shopping. Select the correct answer using the code given below :
UPSC's answer: (a) — Let the total number of members be 100%. The percentage of members who went for shopping is 80%, and for sightseeing is 50%. The percentage of members who took rest is 10%, meaning 90% of members were active (shopping or sightseeing or both).
In a school, 60% students play cricket. A student who does not play cricket, plays football. Every football player has got a two-wheeler. Which of the following conclusions cannot be drawn from the above data ? 1. 60% of the students do not have two-wheelers. 2. No cricketer has a two-wheeler. 3. Cricket players do not play football. Select the correct answer using the code given below :
UPSC's answer: (d) — 60% of students play cricket; the students who do not play cricket (40%) play football, and every football player has a two-wheeler. Conclusion 1 cannot be drawn: cricketers may also own two-wheelers, so we cannot say that 60% do not have one.
The ratio of a two-digit natural number to a number formed by reversing its digits is 4 : 7. The number of such pairs is
UPSC's answer: (b) — Let the number be 10x + y; the number with its digits reversed is 10y + x. (10x + y) : (10y + x) = 4 : 7 gives 70x + 7y = 40y + 4x, so 66x = 33y, that is y = 2x. Since y must be a single digit, x can be 1, 2, 3 or 4, giving 12, 24, 36 and 48 (x = 5 would make y = 10).
In an examination, A has scored 20 marks more than B. If B has scored 5% less marks than A, how much has B scored ?
UPSC's answer: (b) — A scored 20 marks more than B, and B scored 5% less than A, so the 20-mark gap is 5% of A's score. A = 20 ÷ 0·05 = 400, so B = 400 − 20 = 380, option (b).
Seeta and Geeta go for a swim after a gap of every 2 days and every 3 days respectively. If on 1ˢᵗ January both of them went for a swim together, when will they go together next ?
UPSC's answer: (d) — 'After a gap of every 2 days' means two rest days between swims, so Seeta swims every 3rd day: 1, 4, 7, 10, 13 January. 'After a gap of every 3 days' means three rest days between swims, so Geeta swims every 4th day: 1, 5, 9, 13 January.
X, Y and Z are three contestants in a race of 1000 m. Assume that all run with different uniform speeds. X gives Y a start of 40 m and X gives Z a start of 64 m. If Y and Z were to compete in a race of 1000 m, how many metres start will Y give to Z ?
UPSC's answer: (b) — X gives Y a start of 40 m in a 1000 m race, meaning when X covers 1000 m, Y covers 960 m; hence the speed ratio X : Y = 1000 : 960 = 25 : 24. X gives Z a start of 64 m in a 1000 m race, meaning when X covers 1000 m, Z covers 936 m; hence the speed ratio X : Z = 1000 : 936 = 125 : 117.
If x is greater than or equal to 25 and y is less than or equal to 40, then which one of the following is always correct ?
UPSC's answer: (c) — Given the constraints, the minimum value of x is 25 and the maximum value of y is 40. To determine the maximum possible value of (y - x), we use the maximum y and minimum x: 40 - 25 = 15. Since y cannot exceed 40 and x cannot be less than 25, the difference (y - x) can never be greater than 15.
Ena was born 4 years. after her parents' marriage. Her mother is three years younger than her father and 24 years older than Ena, who is 13 years old. At what age did Ena's father get married ?
UPSC's answer: (b) — Ena is currently 13 years old, and her mother is 24 years older than her, making the mother's current age 13 + 24 = 37 years. The mother is three years younger than the father, so the father's current age is 37 + 3 = 40 years.
Rakesh had money to buy 8 mobile handsets of a specific company. But the retailer offered very good discount on that particular handset. Rakesh could buy 10 mobile handsets with the amount he had. What was the discount the retailer offered ?
UPSC's answer: (b) — Let the original price of one mobile handset be P and the total amount Rakesh had be M. Initially, Rakesh could buy 8 handsets, so M = 8P. After the discount, he could buy 10 handsets with the same amount M, so M = 10 * (Discounted Price).
The average marks of 100 students are given to be 40. It was found later that marks of one student were 53 which were misread as 83. The corrected mean marks are
UPSC's answer: (b) — Original total marks = 100 × 40 = 4000. The misread entry added 83 instead of 53, overstating total by 83 − 53 = 30. Corrected total = 4000 − 30 = 3970. Corrected mean = 3970 ÷ 100 = 39.7. Therefore the official key option (b) follows.
Which one of the following is the most logical, rational and crucial message conveyed by the above passage ?
UPSC's answer: (a) — The passage identifies the 'Intellectual Property Rights' regime and corporate profit motives as the primary obstacles to the widespread adoption of GM technology.
On the basis of the above passage, the following assumptions have been made : 1. The issue of effects of natural calamities on agriculture is not given due consideration by GM technology companies. 2. In the long run, GM technology will not be able to solve agricultural problems arising due to global warming. Which of the above assumptions is/are valid ?
UPSC's answer: (a) — The passage states that corporations invest in herbicide-tolerant and pest-resistant crops because these traits have a 'short window' before pests evolve, which suits their profit-maximizing goals.
Which one of the following is the most logical and rational inference that can be made from the above passage ?
UPSC's answer: (c) — The passage states that most invasive species are neither terribly successful nor very harmful and often cause less nuisance than vigorous native plants like bracken.
On the basis of the above passage, the following assumptions have been made : 1. Food safety is a complex issue that calls for a multipronged solution. 2. Great investments need to be made in developing the manpower for surveillance and training. 3. India needs to make sufficient legislation for governing food processing industry. Which of the above assumptions is/are valid ?
UPSC's answer: (a) — Assumption 1 is valid because the passage lists multiple distinct causes of diarrhoeal deaths, including groundwater contamination, unsafe agricultural chemicals, poor hygiene in storage, and unhygienic cooking environments, indicating a complex issue requiring a multipronged solution.
The passage seems to argue
UPSC's answer: (d) — The passage says our cities are planned through the static Development Plan, which draws only on technical expertise and is distanced from people's lived experiences and needs.
The above passage seems to imply that 1. most of modern economic growth is based on technological progress. 2. much of modern Indian economy does not nurture sufficient symbiotic relationship with labour-intensive, natural resource-based livelihoods. 3. service sector in India is not very labour-intensive. 4. literate rural population is not willing to enter organised sector. Which of the statements given above are correct ?
UPSC's answer: (c) — The passage highlights that despite high economic growth (7-8%), organised sector employment growth declined to 1%, indicating that growth is not generating proportional jobs in the formal sector.
Which one of the following is the most logical, rational and crucial inference that can be derived from the above passage ?
UPSC's answer: (c) — The passage states that banking correspondents (BCs) must not ignore investing in financial education and literacy to succeed in bringing hinterland people into the banking fold.
What is X in the sequence 132, 129, 124, 117, 106, 93, X ?
UPSC's answer: (c) — Calculate the differences between consecutive terms: 132 - 129 = 3, 129 - 124 = 5, 124 - 117 = 7, 117 - 106 = 11, 106 - 93 = 13. Observe that the differences are consecutive prime numbers: 3, 5, 7, 11, 13. Identify the next prime number in the sequence, which is 17.
A wall clock moves 10 minutes fast in every 24 hours. The clock was set right to show the correct time at 8:00 a.m. on Monday. When the clock shows the time 6:00 p.m. on Wednesday, what is the correct time ?
UPSC's answer: (a) — From 8:00 a.m. Monday to 6:00 p.m. Wednesday the clock shows 58 hours (48 + 10). The clock gains 10 minutes in every 24 hours, so it shows 24 hours 10 minutes (1450 minutes) for every 1440 real minutes.
If the numerator and denominator of a proper fraction are increased by the same positive quantity which is greater than zero, the resulting fraction is
UPSC's answer: (b) — Let the proper fraction be a/b, where 0 < a < b. Let the positive quantity added to both numerator and denominator be x, where x > 0. The new fraction becomes (a + x) / (b + x).
What is X in the sequence 4, 196, 16, 144, 36, 100, 64, X ?
UPSC's answer: (b) — Split the sequence into two alternating subsequences: odd positions 4, 16, 36, 64 and even positions 196, 144, 100, X. Odd-position terms are squares of consecutive even numbers: 2² = 4, 4² = 16, 6² = 36, 8² = 64.
In a group of 15 people; 7 can read French, 8 can read English while 3 of them can read neither of these two languages. The number of people who can read exactly one language is
UPSC's answer: (b) — Total people = 15; those who read neither = 3, so those who read at least one language = 15 - 3 = 12. Let F = French readers = 7, E = English readers = 8. Using the inclusion-exclusion principle: |F ∪ E| = |F| + |E| - |F ∩ E|.
A printer numbers the pages of a book starting with 1 and uses 3089 digits in all. How many pages does the book have ?
UPSC's answer: (c) — Pages 1 to 9 use 9 digits; pages 10 to 99 use 90 × 2 = 180 digits; pages 100 to 999 use 900 × 3 = 2700 digits. Up to page 999 the printer uses 9 + 180 + 2700 = 2889 digits. The remaining 3089 − 2889 = 200 digits go on four-digit page numbers, so there are 200 ÷ 4 = 50 more pages.
Consider the following sequence that follows some arrangement : c_accaa_aa_bc_b The letters that appear in the gaps are
UPSC's answer: (b) — Filling the gaps with c, b, b, b gives c c a c c a a b a a b b c b b. Split into groups of five letters: ccacc | aabaa | bbcbb.
A family has two children along with their parents. The average of the weights of the children and their mother is 50 kg. The average of the weights of the children and their father is 52 kg. If the weight of the father is 60 kg, then what is the weight of the mother ?
UPSC's answer: (d) — Children + mother = 3 × 50 = 150 kg, and children + father = 3 × 52 = 156 kg. The father weighs 60 kg, so the two children together weigh 156 − 60 = 96 kg. Mother = 150 − 96 = 54 kg, option (d).
Suppose you have sufficient amount of rupee currency in three denominations : ₹ 1, ₹ 10 and ₹ 50. In how many different ways can you pay a bill of ₹ 107 ?
UPSC's answer: (c) — Let the bill be paid with x notes of ₹ 50 and y notes of ₹ 10, with the rest in ₹ 1; the ₹ 1 part is fixed once x and y are chosen, so we count the pairs with 50x + 10y ≤ 107. x = 0: y can be 0 to 10, giving 11 ways. x = 1: 10y ≤ 57, so y can be 0 to 5, giving 6 ways.
'A' started from his house and walked 20 m towards East, where his friend 'B' joined him. They together walked 10 m in the same direction. Then 'A' turned left while 'B' turned right and travelled 2 m and 8 m respectively. Again 'B' turned left to travel 4 m followed by 5 m to his right to reach his office. 'A' turned right and travelled 12 m to reach his office. What is the shortest distance between the two offices ?
UPSC's answer: (b) — A starts at (0,0), walks 20 m East to (20,0), then 10 m East with B to (30,0). A turns left (North) and walks 2 m to (30,2); B turns right (South) and walks 8 m to (30,-8). B, facing South, turns left (East) and walks 4 m to (34,-8), then turns right (South) and walks 5 m to his office at (34,-13).
Consider two statements S1 and S2 followed by a question : S1 : p and q both are prime numbers. S2 : p + q is an odd integer. Question : Is pq an odd integer? Which one of the following is correct ?
UPSC's answer: (b) — S2 states that p + q is an odd integer. For the sum of two integers to be odd, exactly one of them must be even and the other must be odd. If one of p, q is even and the other is odd, then their product pq = (even) × (odd) is necessarily even.
Which year has the same calendar as that of 2009 ?
UPSC's answer: (d) — A calendar repeats when the total number of odd days (remainder of days divided by 7) between the two years is zero. From 2009 to 2015, there are 6 intervening years: 2009, 2010, 2011, 2012, 2013, and 2014.
Number 136 is added to 5B7 and the sum obtained is 7A3, where A and B are integers. It is given that 7A3 is exactly divisible by 3. The only possible value of B is
UPSC's answer: (d) — The equation is 136 + 5B7 = 7A3, which simplifies to 5B7 = 7A3 - 136. Performing the subtraction: 7A3 - 136 results in a number ending in 7 (since 13 - 6 = 7), confirming the units digit of 5B7 is 7.
Which one of the following is the most logical, rational and crucial inference that can be derived from the above passage ?
UPSC's answer: (b) — The passage explicitly states that in today's hyper-competitive global economy, regulations need to be viewed as 'weapons' that seek cost-justified social and environmental benefits while improving economic well-being.
On the basis of the above passage, the following assumptions have been made : In today's global economy, 1. regulations are not effectively used to protect local markets. 2. social and environmental concerns are generally ignored by the governments across the world while implementing the regulations. Which of the above assumptions is/are valid ?
UPSC's answer: (d) — The passage states that regulations 'may be used to protect local markets,' which implies that such usage is possible and occurs, thereby invalidating Assumption 1 which claims they are 'not effectively used' for this purpose.
Which one of the following is the most logical, rational and crucial inference that can be derived from the above passage ?
UPSC's answer: (d) — The passage establishes a causal link: malnourished mothers produce milk with low sialylated oligosaccharides, leading to immature infant microbiomes, which in turn causes malnutrition in babies.
On the basis of the above passage, the following assumptions have been made : 1. Processed probiotic foods are a solution to treat the children suffering from malnutrition due to immature gut bacteria composition. 2. The babies of malnourished mothers generally tend to be malnourished. Which of the above assumptions is/are valid?
UPSC's answer: (b) — Assumption 2 is valid because the passage explicitly states that malnourished mothers have low levels of sialylated oligosaccharides in their milk, which prevents the infant's microbiome from maturing, leading to malnourished babies.
On the basis of the above passage, the following assumptions have been made : 1. Regions of glaciers warm faster than other regions due to global warming. 2. Global warming can lead to seafloor sedimentation in some areas. 3. Melting glaciers can reduce marine biodiversity in some areas. Which of the above assumptions is/are valid?
UPSC's answer: (c) — Assumption 1 is invalid because the passage states that the Western Antarctic Peninsula warmed faster than the global average, but it does not generalize that all glacier regions warm faster than other regions.
On the basis of the above passage, the following assumptions have been made : 1. Global warming is a frequently occurring natural phenomenon. 2. The impending global warming will not adversely affect small mammals. 3. Humans are responsible for the loss of the Earth's natural resilience. Which of the above assumptions is/are valid ?
UPSC's answer: (b) — Assumption 1 is invalid because the passage mentions a specific instance of rapid warming 13,000 years ago but does not provide evidence that global warming is a 'frequently occurring' phenomenon.
On the basis of the above passage, the following assumptions have been made : 1. Humans have been the main reason for the large scale extinction of plant species. 2. Consumption of food mainly from locally cultivated crops ensures crop diversity. 3. The present style of production and distribution of food will finally lead to the problem of food scarcity in the near future. 4. Our food security may depend on our ability to preserve the locally cultivated varieties of crops. Which of the above assumptions are valid ?
UPSC's answer: (b) — Assumption 1 is invalid because the passage attributes the extinction to 'heavy dependence on a few high yielding varieties and technology-driven production,' not to humans as a general category or other factors like natural disasters.
If every alternative letter of the English alphabet from B onwards (including B) is written in lower case (small letters) and the remaining letters are capitalized, then how is the first month of the second half of the year written ?
UPSC's answer: (d) — The first month of the second half of the year (July–December) is July, so the word to be written is JULY. The rule states that every alternative letter from B onwards (including B) is written in lower case.
Sunita cuts a sheet of paper into three pieces. Length of first piece is equal to the average of the three single digit odd prime numbers. Length of the second piece is equal to that of the first plus one-third the length of the third. The third piece is as long as the other two pieces together. The length of the original sheet of paper is
UPSC's answer: (d) — The single-digit odd prime numbers are 3, 5 and 7; their average is 5, so the first piece is 5 units long. Let the third piece be t units; the second piece is 5 + t/3. The third piece equals the other two together: t = 5 + 5 + t/3, so 2t/3 = 10 and t = 15.
In the sequence 1, 5, 7, 3, 5, 7, 4, 3, 5, 7, how many such 5s are there which are not immediately preceded by 3 but are immediately followed by 7 ?
UPSC's answer: (a) — The sequence is: 1, 5, 7, 3, 5, 7, 4, 3, 5, 7. We need to find 5s that are immediately followed by 7. The 5s followed by 7 are at positions 2 (1, 5, 7), 5 (3, 5, 7), and 9 (3, 5, 7). Check the preceding number for each: Position 2 is preceded by 1 (not 3), so it qualifies.
A joint family consists of seven members A, B, C, D, E, F and G with three females. G is a widow and sister-in-law of D's father F. B and D are siblings and A is daughter of B. C is cousin of B. Who is E ? 1. Wife of F 2. Grandmother of A 3. Aunt of C Select the correct answer using the code given below :
UPSC's answer: (d) — B and D are siblings, so both are children of F; A is B's daughter. G is a widow and F's sister-in-law: she is the wife of F's late brother, and C, the cousin of B, is her child. The three females are A, G and one more; the mother of B and D must be that third female, and the only member left is E.
Each face of a cube can be painted in black or white colours. In how many different ways can the cube be painted ?
UPSC's answer: (b) — The problem asks for the number of distinct colorings of a cube's faces using two colors (black and white), where rotations of the cube are considered identical. We classify the distinct cubes by the number of black faces (k), ranging from 0 to 6.
How many triplets (x, y, z) satisfy the equation x + y + z = 6, where x, y and z are natural numbers ?
UPSC's answer: (d) — Let x, y, z be natural numbers, i.e., positive integers at least 1. Put x' = x - 1, y' = y - 1, z' = z - 1, so x', y', z' are non-negative integers. The equation becomes x' + y' + z' = 6 - 3 = 3. The number of non-negative integer solutions to x' + y' + z' = 3 is C(3 + 3 - 1, 3 - 1) = C(5, 2) = 10.
If $ means 'divided by'; @ means 'multiplied by'; # means 'minus', then the value of 10#5@1$5 is
UPSC's answer: (d) — The expression is 10#5@1$5, where # means minus, @ means multiplied by, and $ means divided by. Substituting the standard operators, the expression becomes 10 - 5 * 1 / 5. According to the order of operations (BODMAS/PEMDAS), division and multiplication are performed before subtraction.
An 8-digit number 4252746B leaves remainder 0 when divided by 3. How many values of B are possible ?
UPSC's answer: (c) — The divisibility rule for 3 states that a number is divisible by 3 if the sum of its digits is divisible by 3. Calculate the sum of the known digits: 4 + 2 + 5 + 2 + 7 + 4 + 6 = 30. The total sum of the digits is 30 + B. For the number to be divisible by 3, (30 + B) must be a multiple of 3.
If F stands second in the ranking, then the position of B is
UPSC's answer: (c) — The condition 'Either C or F scores the highest' implies that if F is not the highest, C must be the highest. Since F is stated to stand second, C must be the highest (1st position). The rule 'Whenever C scores the highest, then E scores the least' places E in the 6th position.
If B scores the least, the rank of C will be
UPSC's answer: (d) — If B scores the least, C cannot be the highest (then E would be the least), so F is the highest. Ranks 2 to 5 go to C, D, A and E. D is just above A (close competitors) and C is above A, so D and A cannot be 2nd and 3rd.
If E is ranked third, then which one of the following is correct ?
UPSC's answer: (b) — Since E is ranked third, C cannot be highest because if C is highest then E is least (rank 6). Therefore F is highest (rank 1), and B is least (rank 6). The remaining ranks 2, 4 and 5 are for A, C and D, with C > A, D > A, and D immediately above A as close competitors.
Which one of the following statements is correct ?
UPSC's answer: (d) — Read the statements as: twice Sohan's weight is less than both Mohan's and Rohan's weights (S1), and twice Rohan's weight is greater than both Mohan's and Sohan's weights (S2). From S1 Sohan is lighter than both others, so he cannot be the heaviest.
Which one of the following statements is correct ?
UPSC's answer: (b) — S1 says twice Sohan's weight is less than Mohan's weight and less than Rohan's weight. So Sohan weighs less than half of Mohan and less than half of Rohan, and is lighter than both of them. Hence Sohan's weight is the least, option (b).
Question paper and answer key: Union Public Service Commission. Explanations: UPSC Answer Check. Practise this paper with a timer →
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