CSAT 2021
UPSC Prelims CSAT 2021 Solution
The UPSC Prelims CSAT 2021 Solution provides comprehensive answers and explanations for the Civil Services Aptitude Test conducted in 2021. It is an essential resource for aspirants to analyze their performance, understand the correct approaches to questions, and prepare effectively for future examinations.
Prelims CSAT 2021 Solution
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- Consider all 3-digit numbers (without repetition of digits) obtained using three non-zero digits) obtained using three non-zero digits which are multiples of 3. Let S be their sum.
- There are two Classes A and B having 25 and 30 students respectively. In Class-A the highest score is 21 and lowest score is 17. In Class-B the highest score is 30 and lowest score is 22. Four students are shifted from Class-A to Class-B.
- A student appeared in 6 papers. The maximum marks are the same for each paper. His marks in these papers are in the proportion 5 : 6 : 7 : 8 : 9 : 10. Overall he scored 60%. In how many number of papers did he score less than 60% of the maximum marks?
- A boy plays with a ball, and he drops if from a height of 1.5 m.
- Integers are listed from 700 to 1000. In how many integers is the sum of the digits 10?
- If 3^2019 is divided by 10, then what is the remainder?
- The number 3798125P369 is divisible by 7. What is the value of the digit P?
- From January 1, 2021, the price of petrol (in Rupees per litre) on mth day of the year is 80 + 0.1m, where m = 1, 2, 3, …, 100 and thereafter remains constant. On the other hand, the price of diesel (in Rupees per litre) on nth day of 2021 is 69 + 0.15n for any n. On which date in the year 2021 are the prices of these two fuels equal?
- A biology class at high school predicted that a local population of animals will double in size every 12 years.
- A pie diagram shows the percentage distribution of proteins, water and on the dry elements in the human body.
- The difference between a 2-digit number and the number obtained by interchanging the positions of the digits is 54.
- If the price of an article is decreased by 20% and then the new price is increased by 25%, then what is the net change in the price?
- When a certain number is multiplied by 7, the product entirely comprises ones only (1111…). What is the smallest such number?
- On a chess board, in how many different ways can 6 consecutive squares be chosen on the diagonals along a straight path ?
- Using 2, 2, 3, 3, 3 as digits, how many distinct numbers greater than 30000 can be formed?
- Consider the following statements : 1. The sum of 5 consecutive integers can be 100.
- A cubical vessel of side 1 m is filled completely with water. How many millilitres of water is contained in it (neglect thickness of the vessel) ?
- There are 6 persons arranged in a row. Another person has to shake hands with 3 of them so that he should not shake hands with two consecutive persons. In how many distinct possible combinations can the handshakes take place?
- An amount of money was distributed among A, B and c in the ratio p : q : r.
- Jay and Vijay spent an equal amount of money to buy some pens and special pencils of the same quality from the same store. If Jay bought 3 pens and 5 pencils, and Vijay bought 2 pens and 7 pencils, then which one of the following is correct ?
- A person P asks one of his three friends X as to how much money he had. X replied, “If Y given me Rs. 40, then Y will have half of as much as Z, but if Z gives me Rs. 40, then three of us will have equal amount.” What is the total amount of money that X, Y and Z have ?
- In an objective type test of 90 questions, 5 marks are allotted for every correct answer and 2 marks are deducted for every wrong answer. After attempting all the 90 questions, a student got a total of 387 marks. What is the number of incorrect response ?
- Consider the following addition problem : 3P+4P+PP+PP=PQ2; where P, Q and R are different digits.
- Consider the following multiplication problem : (PQ)×3=RQQ, where P, Q and R are different digits and R≠ 0.
- What is the value of ‘X’ in the sequence 2, 7, 22, 67, 202, X, 1822?
- In a group of 120 persons, 80 are Indians and rest are foreigners. Further, 70 persons in the group can speak English. The number of Indians who can speak English is
- Question: What is Seema’s rank from the top in the class of 40 students?
- Question: Who is the heaviest among A, B, C, D and E?
- In the English alphabet, the first 4 letters are written in opposite order, and the next 4 letters are written in opposite order and so on; and at the end Y and Z are interchanged. Which will be the fourth letter to the right of the 13th letter?
- Seven books P, Q, R, S, T, U and V are placed side by side. R, Q and T have blue covers and other books have red covers. Only S and U are new books and the rest are old. P, R and S are law reports; the rest are Gazetteers. Books of old Gazetteers with blue covers are
- Replace the incorrect term by the correct term in the given sequence 3, 2, 7, 4, 13, 10, 21, 18, 31, 28, 43, 40 where odd terms and even terms follow the same pattern.
- Following is a matrix of certain entries. The entries follow a certain trend row-wise. Choose the missing entry (?) accordingly.
- You are given two identical sequences in two rows: Sequence-I: 8 4 6 15 52.5 236.5 Sequence-II: 5 A B C D E
- A person X from a place A and another person Y from a place B set out at the same time to walk towards each other.
- Statement: Some cats are almirahs. Some almirahs are chairs. All chairs are tables.
- Images of consonants of the English alphabet (Capitals) are observed in a mirror. What is the number of images of these which do not look like their original shapes?
- A bank employee drives 10 km towards South from her house and turns to her left and drives another 20 km.
- A woman runs 12 km towards her North, then 6 km towards her South and then 8 km towards her East. In which direction is she from her starting point?
- In a class, 60% of students are from India and 50% of the students are girls. If 30% of the Indian students are girls, then what percentage of foreign students are boys?
- Statement: Some radios are mobiles. All mobiles are computers. Some computers are watches.
- Joseph visits the club on every 5th day, Harsh visits on every 24th day, while Sumit visits on every 9th day. If all three of them met at the club on a Sunday, then on which day will all three of them meet again ?
- X said to Y, “”At the time of your birth I was twice as old as you are at present.”” If the present age of X is 42 years, then consider the following statements:
- A man completes 7/8 of a job in 21 days. How many more days will it take him to finish the job if quantum of work is further increased by 50%
- There are three points P,Q and R on a straight line such that PQ:QR-3:5. If n is the number of possible values of PQ:PR, then what is n equal to ?
- In the series_b_a_ba_b_abab_aab; fill in the six blanks (_) using one of the following given four choices such that the series follows a specific order.
- P scored 40 marks more than Q in an examination. If Q scored 10% less marks than P, then how much did Q score.
- In a code language ‘MATHEMATICS’ is written as ‘LBSIDNZUHDR’. How is CHEMISTRY’ written in that code language?
- At which one of the following times, do the hour hand the minute hand of the clock make an angle of 180° with each other?
- Half of the villagers of a certain village have their own houses. One-fifth of the villagers cultivate paddy. One-third of the villagers are literate. Four-fifth of the villagers are under 25 years of age. Which one of the following statements is certainly correct?
- Consider two Statements and a Question: Statement 1: The last day of the month is a Wednesday. Statement 2: The third Saturday of the month was the seventeenth day. Question: What day is the fourteenth of the given month?
- Which day is 10th October, 2027 ?
- With respect to what are called denomination of religion, if everyone is left to be a judge of his own religion, there is no such things as religion that is wrong; but if they are to be a judge of each other’s religion, there is no such thing as a religion that is right, and therefore all the world is right or all the world is wrong in the matter of religion.
- It is certain, that sedition, wars, and contempt or breach of the laws are not so much to be imputed to the wickedness of the subjects, as to the bad state of a dominion.
- Inequality violates a basic democratic norm: the equal standing of citizens.
- Aristocratic government ruins itself by limiting too narrowly the circle within which power is confined; oligarchic government ruins itself by the incautious scramble for immediate wealth.
- India faces a challenging immediate future in energy and climate policy-making.
- There are reports that some of the antibiotics sold in the market are fed to poultry and other livestock as growth promoters.
- Policy makers and media have placed the blame for skyrocketing food prices on a variety of factors, including high fuel prices, bad weather in key food producing countries, and the diversion of land to non-food production.
- A central message of modern development economics is the importance of income growth, by which is meant growth in Gross Domestic Product (GDP).
- Fig trees (genus Ficus) are considered sacred in India, East Asia and Africa and are common in agricultural and urban landscapes where other large trees are absent.
- At the heart of agroecology is the idea that agroecosystems should mimic the biodiversity levels and functioning of natural ecosystems.
- Computers increasingly deal not just with abstract data like credit card details and databases, but also with the real world of physical objects and vulnerable human bodies.
- A social and physical environment riddled with poverty, inequities, unhygienic and insanitary conditions generates the risk of infectious diseases.
- Researchers simulated street lighting on artificial grassland plots containing pea-aphids, sap-sucking insects, at night.
- Approximately 80 percent of all flowering plant species are pollinated by animals, including birds and mammals, but the main pollinators are insects.
- A study conducted on the impacts of climate change over the Cauvery basin of Tamil Nadu using regional climate models showed an increasing trend for maximum and minimum temperatures, and a decrease in the number of rainy days.
- Researchers were able to use stem cells to gauge the neurotoxic effects of the environmental pollutants Bisphenol A (BPA).
- Medieval merchants risked the hazards of the Silk Road to reach the markets of China; Portuguese caravels in the 15th century sailed beyond the bounds of the known world, searching less for knowledge than for gold and spices.
- …….. most people would agree that telling deliberate lies is wrong, except perhaps in certain special situations where more harm will be done by telling the truth.
- Can a democracy avoid being a welfare state for long?
- In our schools, we teach our children all that is there to know no about Physics, maths and history and what-have you.
- The best universities like Harvard and MIT,
- Our cities are extremely vulnerable to climate change because of large concentrations of populations and poor infrastructure.
- Nothing can exist in a natural state,
- In the immediate future, we will see the increasing commodification of many new technologies –
- The resolution of bankruptcy cases of Indian banks under the Insolvency and Bankruptcy Code should help bring non-performing assets (NPA) situation under some control.
- In India, the objective of macroeconomics policy is to enhance the economic welfare of the people, and any one wing of such macro policy, monetary or fiscal, cannot independently work without active support of another.