CSAT (Paper II): previous-year questions
1280 real UPSC Prelims questions (2011–2026) with the official answer and a clear explanation. 400 of them came in the last five papers.
How often UPSC asks this
Questions per year, counted from the official papers.
Subtopics
Arrangements, ranking, ordering and puzzles
142 questions
Clocks and calendars
5 questions
Coding-decoding, series, patterns, cubes, dice and visual reasoning
110 questions
Communication, interpersonal skills and decision-making
10 questions
Counting, permutations, combinations and probability
1 questions
Directions, blood relations and Venn diagrams
60 questions
General English: grammar, vocabulary and comprehension
20 questions
General Hindi: grammar, vocabulary, dialects and comprehension
25 questions
Geometry and mensuration
26 questions
Number system and basic algebra (divisibility, HCF/LCM, remainders, digits, equations)
196 questions
Percentages, profit and loss, discount, simple and compound interest
47 questions
Ratio, proportion, averages, mixtures and alligation
47 questions
Syllogisms, statements and conclusions, assumptions and arguments
89 questions
Time and work; pipes and cisterns
2 questions
Time, speed and distance; trains, boats and streams; races
48 questions
Attempt the questions
Newest papers first. Tap an option; the answer and the reason appear instantly.
Read the passage
Today, if we consider cities such as New York, London and Paris as some of the most iconic cities in the world, it is because plans carrying a heavy systems approach were imposed on their precincts. The backbone of the systems theory is the process of translating social, spatial and cultural desirables into mathematical models using computing, statistics, optimization and an algorithmic way of formulating and solving problems. The early universities of the West which began to train professionals in planning, spawned some of the most ingenious planners, who were experts in these domains. This was because these very subjects were absorbed into the planning curriculum that had its roots in the social sciences, geography and architecture. Planning in India, and its education differ from the West.
Which one of the following statements best reflects the most logical and rational inference that can be made from the above passage?
Answer (a) & explanation
The best inference is that urban planning courses need a diverse, interdisciplinary approach (a). Step 1: the passage says cities like New York, London and Paris became iconic through a systems approach: computing, statistics and maths. Step 2: Western universities produced great planners because these subjects were added to a curriculum rooted in social sciences, geography and architecture. That is a mix of fields, so (a). Step 3: options (b) bureaucracy, (c) funds and (d) population and poverty bring in outside facts the passage never mentions.
Tip: an inference must come from the passage itself. Reject options that may be true about India but are not in the text. "Interdisciplinary" means combining many subjects.
Answer as per the official UPSC answer key.
Read the passage
When a child reaches adolescence, there is apt to be a conflict between the parents and the child, since the latter considers himself to be by now quite capable of managing his own affairs, while the former are filled with parental solicitude, which is often a disguise for love of power. Parents consider, usually, that the various moral problems which arise in adolescence are peculiarly their province. The options they express, however, are so dogmatic that the young seldom confide in them, and usually go their own way in secret.
Based on the above passage, the following assumptions have been made :
- 1. The adolescent does not feel comfortable with his parents because they tend to be dominating and assertive.
- 2. The adolescent of modern times does not have much respect for parents.
Which of the assumptions given above is/are valid?
Answer (a) & explanation
Only assumption 1 is valid (a). Step 1: the passage says parental care is "often a disguise for love of power" and parents' opinions are "so dogmatic" that the young seldom confide in them. So the adolescent is uneasy because parents are dominating (1). Step 2: assumption 2 says adolescents lack respect for parents. The passage speaks of not confiding, not of disrespect. Step 3: it also never mentions "modern times". So 2 adds new ideas, and options (b), (c) and (d) fail.
Tip: not confiding in someone is different from not respecting them. Watch for options that swap one feeling for another.
Answer as per the official UPSC answer key.
If a + b means a − b; a − b means a × b; a × b means a ÷ b; a ÷ b means a + b, then what is the value of 10 + 30 − 100 × 50 ÷ 25? (Operations are to be replaced simultaneously)
Answer (d) & explanation
The value is −25 (d). Step 1: replace every sign at the same time: + becomes −, − becomes ×, × becomes ÷, ÷ becomes +. So 10 + 30 − 100 × 50 ÷ 25 becomes 10 − 30 × 100 ÷ 50 + 25. Step 2: do × and ÷ first (BODMAS): 30 × 100 = 3000, ÷ 50 = 60. Step 3: 10 − 60 + 25 = −25. Options (a), (b) and (c) come from changing signs one at a time or ignoring the order of operations.
Tip: rewrite the whole expression with new signs before calculating. Then apply BODMAS: division and multiplication before addition and subtraction.
replacing one sign at a time changes signs you have already replaced. Swap all of them together.
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Answer as per the official UPSC answer key.
Read the passage
By the time children reach class 8, the bulk of them tend to be in the age range of 13 years to 15 years. But in our country, about a quarter of all children in class 8 struggle with reading simple texts and more than half are still unable to do basic arithmetic operations like division. Every year about 25 million young boys and girls from elementary school move into the life that lies for them beyond compulsory schooling. They cannot enter the workforce at least in the organized sector till they are 18. For many families, these children are the first from their families ever to get this far in school. Parents and children expect that such ‘graduates’ from school will go on to high school and college. Hardly anyone wants to go back to agriculture. On the other hand, abilities in terms of academic competencies are far lower than they should be even based on curricular expectations of class 8.
Which one of the following statements best reflects the central idea conveyed by the passage?
Answer (c) & explanation
The central idea is that policy should align young people's skills with their expectations (c). Step 1: the passage says families expect class 8 "graduates" to go to high school and college, and hardly anyone wants to return to farming. Step 2: but their actual abilities are far below even class 8 level. This gap between expectations and competence is the core problem; fixing it is (c). Step 3: options (a) poverty and (b) money incentives are never discussed. Option (d) wants pass-outs to go back to farming, the opposite of the passage's mood.
Tip: the central idea usually ties together the two halves of a passage. Here: high hopes versus low skills.
Answer as per the official UPSC answer key.
325 + 227 is divisible by
Answer (c) & explanation
The number is divisible by 10 (c). Step 1: write everything as powers of 2. 32 = 2⁵, so 32⁵ = 2²⁵. Step 2: 2²⁵ + 2²⁷ = 2²⁵ × (1 + 2²) = 2²⁵ × (1 + 4) = 5 × 2²⁵. Step 3: it has a factor 5 and a factor 2, so it is divisible by 10. It has no factor 3, 7 or 11, so options (a), (b) and (d) fail.
Tip: when the bases are powers of the same number, convert them to one base. Then take out the smaller power as a common factor. This turns a huge sum into a simple product.
when the bases differ, check if they are powers of the same number.
Answer as per the official UPSC answer key.
Read the passage
According to the Food and Agriculture Organization, one-third of food produced for human consumption is lost or wasted globally. Food is lost or wasted throughout the supply chain, from initial agricultural production to final household consumption. The increasing wastage also results in land degradation by about 45%, mainly due to deforestation, unsustainable agricultural practices, and excessive groundwater extraction. The energy spent over wasted food results in about 3·5 billion tonnes of carbon dioxide production every year. Decay also leads to harmful emissions of other gases in the atmosphere. Addressing the loss and wastage of food in all forms is critical to complete the cycle of food sufficiency and food sustainability.
Which of the following statements best reflect the most logical and rational inferences that can be made from the passage?
- 1. The current methods of food distribution are solely responsible for the loss and wastage of food.
- 2. Land productivity is adversely affected by the prevailing trend of food loss and wastage.
- 3. Reduction in the loss and wastage of food results in lesser carbon footprint.
- 4. Post-harvest technologies to prevent or reduce the loss and wastage of food are not available.
Select the correct answer using the code given below.
Answer (b) & explanation
Statements 2 and 3 can be inferred (b). Step 1: the passage says food wastage causes land degradation of about 45%. Damaged land gives less output, so land productivity suffers (2). Step 2: the energy spent on wasted food produces about 3.5 billion tonnes of CO₂ a year. So cutting waste cuts the carbon footprint (3). Step 3: statement 1 fails on the word "solely": food is lost "throughout the supply chain", from farm to household, not only in distribution. Statement 4, about post-harvest technology, is never mentioned. So options (a), (c) and (d) fail.
Tip: words like "solely", "only" and "always" usually make a statement too strong. One-third of the world's food is lost or wasted, as per the FAO.
Answer as per the official UPSC answer key.
Read the passage
Only with long experience and opening of his wares on many a beach where his language is not spoken, will the merchant come to know the worth of what he carries, and what is parochial and what is universal in his choice. Such delicate goods as justice, love and honour, courtesy, and indeed all the things we care for, are valid everywhere but they are variously moulded and often differently handled, and sometimes nearly unrecognizable if you meet them in a foreign land, and the art of learning fundamental common values is perhaps the greatest gain of travel to those who wish to live at ease among their fellows.
When we meet other people while we travel, we learn to differentiate between
Answer (c) & explanation
Travel teaches us to tell local values from universal values (c). Step 1: the passage says the merchant, after opening his wares on many foreign beaches, learns "what is parochial and what is universal". Step 2: "parochial" means local or narrow. The goods are values like justice, love, honour and courtesy, valid everywhere but shaped differently in each land. So (c). Step 3: option (a), imagination and understanding, (b), communities and nationalities, and (d), friends and foes, are not in the passage.
Tip: when a passage uses a hard word, the answer often uses its simple meaning. Parochial = local; universal = common to all. The "merchant" here is a metaphor for the traveller.
Answer as per the official UPSC answer key.
A Question is given followed by two Statements I and II. Consider the Question and the Statements.
A certain amount was distributed among X, Y and Z.
Question : Who received the least amount?
Statement-I : X received 4/5 of what Y and Z together received.
Statement-II : Y received 2/7 of what X and Z together received.
Which one of the following is correct in respect of the above Question and the Statements?
Answer (c) & explanation
Both statements together are needed (c). Step 1: statement I: X = 4/5 of (Y + Z). So X gets 4/9 of the total, but how Y and Z split the rest is unknown. Not enough. Step 2: statement II: Y = 2/7 of (X + Z). So Y gets 2/9 of the total, but X and Z's split is unknown. Not enough. Step 3: together: X = 4/9, Y = 2/9, so Z = 3/9. Y received the least. Options (a), (b) and (d) fail.
Tip: "A gets a/b of what the others get" means A's share = a/(a + b) of the total. This turns ratios into fractions of the whole quickly.
"4/5 of what Y and Z received" is not 4/5 of the total. Convert it: 4 parts against 5 parts means 4/9.
Answer as per the official UPSC answer key.
Read the passage
Today, if we consider cities such as New York, London and Paris as some of the most iconic cities in the world, it is because plans carrying a heavy systems approach were imposed on their precincts. The backbone of the systems theory is the process of translating social, spatial and cultural desirables into mathematical models using computing, statistics, optimization and an algorithmic way of formulating and solving problems. The early universities of the West which began to train professionals in planning, spawned some of the most ingenious planners, who were experts in these domains. This was because these very subjects were absorbed into the planning curriculum that had its roots in the social sciences, geography and architecture. Planning in India, and its education differ from the West.
Based on the above passage, the following assumptions have been made :
- 1. India needs a new generation of urban professionals with knowledge relevant to modern urban practice.
- 2. Indian universities at present have no capacity or potential to impart training in systems approach.
Which of the assumptions given above is/are correct?
Answer (a) & explanation
Only assumption 1 is valid (a). Step 1: the passage praises Western planning education and then says "Planning in India, and its education differ from the West." This implies India needs planners trained in modern methods, so assumption 1 holds. Step 2: assumption 2 says Indian universities have "no capacity or potential". The passage only says Indian education is different; it never says it is incapable. Step 3: so assumption 2 is far too strong. Options (b), (c) and (d) fail.
Tip: "different" is not "incapable". Extreme words like "no capacity", "never" and "impossible" usually make an assumption invalid. India's cities are growing fast, which raises the need for skilled planners.
Answer as per the official UPSC answer key.
Read the passage
When a child reaches adolescence, there is apt to be a conflict between the parents and the child, since the latter considers himself to be by now quite capable of managing his own affairs, while the former are filled with parental solicitude, which is often a disguise for love of power. Parents consider, usually, that the various moral problems which arise in adolescence are peculiarly their province. The options they express, however, are so dogmatic that the young seldom confide in them, and usually go their own way in secret.
Which one of the following statements best reflects the central idea of the above passage?
Answer (a) & explanation
The central idea is that parents may not be of much help as children grow into adults (a). Step 1: the passage shows adolescents feel able to manage their own lives, while parents are dogmatic. Step 2: so the young "seldom confide" in parents and go their own way in secret. Parents end up of little help, which is (a). The word "may" keeps it suitably mild. Step 3: option (b) says parents' involvement is "unnecessary", which is too absolute. Options (c) nuclear families and (d) stubborn adolescents are not discussed.
Tip: prefer moderate words ("may", "often") over absolute ones ("unnecessary", "never") in central-idea questions.
Answer as per the official UPSC answer key.
If P means 'greater than (>)'; Q means 'less than (<)'; R means 'not greater than (≯)'; S means 'not less than (≮)' and T means 'equal to (=)', then consider the following statements :
- 1. If 2x(S)3y and 3x(T)4z, then 9y(P)8z.
- 2. If x(Q)2y and y(R)z, then x(R)z.
Which of the statements given above is/are correct?
Answer (d) & explanation
Neither statement is correct (d). Step 1: decode: P = >, Q = <, R = ≤ (not greater), S = ≥ (not less), T = =. Step 2: statement 1: 2x ≥ 3y and 3x = 4z, so x = 4z/3. Then 8z/3 ≥ 3y, that is 8z ≥ 9y. The claim 9y > 8z is the opposite, so 1 is wrong. Step 3: statement 2: x < 2y and y ≤ z give only x < 2z. Try y = z = 5, x = 8: x < 10 holds, but x > z. So x ≤ z need not hold; 2 is wrong. Options (a), (b) and (c) fail.
Tip: decode symbols first, then test a counter-example. One case that breaks a statement is enough to reject it.
Answer as per the official UPSC answer key.
Read the passage
We take it for granted now that science has a social responsibility. The idea would not have occurred to Newton or Galileo. They thought of science as an account of the world as it is, and the only responsibility that they acknowledged was to tell the truth. The idea that science is a social enterprise is modern, and it begins at the industrial revolution. We are surprised that we cannot trace a social sense further back, because we nurse the illusion that the industrial revolution ended a golden age.
Which one of the following statements best reflects the thinking of the author about the science?
Answer (d) & explanation
The author thinks science must pursue truth and also serve society (d). Step 1: the passage says Newton and Galileo saw science's only duty as "to tell the truth". Step 2: it adds that today "we take it for granted" that science has a social responsibility, an idea that began with the industrial revolution. Joining both gives (d). Step 3: option (c) reverses the link: the passage says the social sense began at the industrial revolution, not that science caused it. Options (a), scientists' commitment, and (b), scientific awareness, are not discussed.
Tip: when a passage moves from an old view to a new one, the best answer often joins both. India's Constitution (Article 51A) lists developing scientific temper as a fundamental duty.
Answer as per the official UPSC answer key.
Let p and q be positive integers satisfying p < q and p + q = k. What is the smallest value of k that does not determine p and q uniquely?
Answer (c) & explanation
The smallest such k is 5 (c). Step 1: p and q are positive whole numbers with p < q. Step 2: k = 3: only 1 + 2, so unique. k = 4: only 1 + 3, because 2 + 2 is not allowed (p must be less than q). Unique again. Step 3: k = 5: both 1 + 4 and 2 + 3 work. Two answers, so k = 5 is the first value that does not fix p and q. Option (b), 4, forgets the p < q rule. Options (a) and (d) are wrong.
Tip: test the smallest cases one by one. Read the conditions carefully: "p < q" rules out equal numbers.
Answer as per the official UPSC answer key.
Read the passage
According to the Food and Agriculture Organization, one-third of food produced for human consumption is lost or wasted globally. Food is lost or wasted throughout the supply chain, from initial agricultural production to final household consumption. The increasing wastage also results in land degradation by about 45%, mainly due to deforestation, unsustainable agricultural practices, and excessive groundwater extraction. The energy spent over wasted food results in about 3·5 billion tonnes of carbon dioxide production every year. Decay also leads to harmful emissions of other gases in the atmosphere. Addressing the loss and wastage of food in all forms is critical to complete the cycle of food sufficiency and food sustainability.
Based on the above passage, the following assumptions have been made :
- 1. The food distribution mechanism needs to be reimagined and made effective to reduce the loss and wastage of food.
- 2. Ensuring the reduction of wastage and loss of food is a social and moral responsibility of all citizens.
Which of the assumptions given above is/are valid?
Answer (c) & explanation
Both assumptions are valid (c). Step 1: the passage says food is lost "from initial agricultural production to final household consumption". The supply side, including distribution, is part of the problem, so it must be made effective (1). Step 2: losses also happen at the household level, so every citizen has a role in cutting waste (2). Step 3: the last line calls tackling waste "critical" for food sufficiency and sustainability, which supports both. So options (a), (b) and (d) fail.
Tip: an assumption is what the author must believe for the argument to hold. If the problem spans the whole chain, action is needed at every link of the chain. Simple habits like cooking only what is needed reduce household waste.
Answer as per the official UPSC answer key.
Read the passage
Only with long experience and opening of his wares on many a beach where his language is not spoken, will the merchant come to know the worth of what he carries, and what is parochial and what is universal in his choice. Such delicate goods as justice, love and honour, courtesy, and indeed all the things we care for, are valid everywhere but they are variously moulded and often differently handled, and sometimes nearly unrecognizable if you meet them in a foreign land, and the art of learning fundamental common values is perhaps the greatest gain of travel to those who wish to live at ease among their fellows.
With reference to the above passage, the following assumptions have been made :
- 1. Travel leads to an understanding of humans.
- 2. Travel helps those who wish to learn fundamental common values.
- 3. A person with long experience in travel can resolve differences amongst people.
Which of the assumptions given above are valid?
Answer (a) & explanation
Assumptions 1 and 2 are valid (a). Step 1: the passage calls "the art of learning fundamental common values" the greatest gain of travel (2). Step 2: it adds this helps those "who wish to live at ease among their fellows", so travel helps us understand people (1). Step 3: assumption 3 says a well-travelled person can resolve differences among others. The passage talks only about the traveller's own understanding, not settling disputes. So options (b), (c) and (d) fail.
Tip: watch for statements that stretch a personal benefit into a social power. Understanding others is not the same as resolving their quarrels.
Answer as per the official UPSC answer key.
A Question is given followed by two Statements I and II. Consider the Question and the Statements.
Question : If the average marks in a class are 60, then what is the number of students in the class?
Statement-I : The highest marks in the class are 70 and the lowest marks are 50.
Statement-II : Exclusion of highest and lowest marks from the class does not change the average.
Which one of the following is correct in respect of the above Question and the Statements?
Answer (d) & explanation
Even both statements together are not enough (d). Step 1: we need the number of students, given the average is 60. Step 2: statement I gives the highest (70) and lowest (50) marks. Statement II says removing them does not change the average. But 70 and 50 themselves average 60, so removing them keeps the average at 60 for any class size. Step 3: so the statements are always consistent but never fix the number. Options (a), (b) and (c) fail.
Tip: when a statement is true for every possible value, it gives no information. Check whether a fact actually narrows the answer.
Answer as per the official UPSC answer key.
Read the passage
Not every voice on the internet commands the same kind of audience. When anonymous private entities with high capital can pay for more space for their opinions, they are effectively buying a louder voice. If political discourse in the digital sphere is a matter of outshining one’s opponent till the election is won, then the quality of politics suffers. The focus of social media is restricted to the promotion of content that generates more user engagement, regardless of how inflammatory the content may be.
Which one of the following statements best reflects the central idea of the above passage?
Answer (b) & explanation
The central idea is that social media are profit-making products, not moral institutions (b). Step 1: the passage says rich entities can pay for space and buy "a louder voice". Step 2: it also says platforms push content that brings engagement, "regardless of how inflammatory" it is. Both show a business that seeks profit, not fairness. Step 3: options (a), (c) and (d) praise social media (instant information, stronger democracy, a necessary part of life). The passage is critical, so they fail.
Tip: first decide the tone of the passage: positive or critical. Then drop every option with the opposite tone. This one passage is critical throughout.
Answer as per the official UPSC answer key.
What is the number of fives used in numbering a 260-page book?
Answer (b) & explanation
There are 56 fives (b). Step 1: count fives in the units place: 5, 15, 25, …, 255. That is one in every 10 pages: 26 fives. Step 2: count fives in the tens place: 50–59, 150–159 and 250–259, ten each: 30 fives. (Pages 55, 155, 255 get counted in both places, which is right, since they each have two fives.) Step 3: the hundreds place has no 5, because pages stop at 260. Total = 26 + 30 = 56. Options (a), (c) and (d) miscount.
Tip: count digit by digit, place by place. Do not try to list numbers; count the units, tens and hundreds places separately.
55 and 155 have two fives each; the place-by-place count handles them without double counting.
Answer as per the official UPSC answer key.
If in a certain code, 'ABCD' is written as 24 and 'EFGH' is written as 1680, then how is 'IJKL' written in that code?
Answer (a) & explanation
IJKL is written as 11880 (a). Step 1: use alphabet positions: A = 1, B = 2, C = 3, D = 4. ABCD = 1 × 2 × 3 × 4 = 24. Step 2: check: E, F, G, H = 5, 6, 7, 8. 5 × 6 × 7 × 8 = 1680. The rule is the product of positions. Step 3: I, J, K, L = 9, 10, 11, 12. 9 × 10 × 11 × 12 = 90 × 132 = 11880. Options (b), (c) and (d) are wrong products.
Tip: in number codes for letters, first try the sum of positions, then the product. Learn the positions: E = 5, J = 10, O = 15, T = 20 (remember "EJOT").
Answer as per the official UPSC answer key.
Consider the sequence
A _ BCD _ BBCDABC _ DABC _ D
that follows a certain pattern. Which one of the following completes the sequence?
Answer (c) & explanation
The blanks are A, A, C, D (c). Step 1: break the sequence into blocks of five letters: A_BCD, _BBCD, ABC_D, ABC_D. Step 2: look for the rule: each block is ABCD with one letter doubled, and the doubled letter moves along: AABCD, ABBCD, ABCCD, ABCDD. Step 3: so the blanks are A, A, C, D. Option (d), A, A, D, C, swaps the last two. Options (a) and (b) break the first blocks.
Tip: in letter-series blanks, try splitting the line into equal blocks of 4, 5 or 6. A pattern usually shows up once the blocks line up.
Answer as per the official UPSC answer key.