UPSC Prelims PYQs with explanations
Real questions from official papers, mapped to syllabus topics. Attempt each one; the answer and the reason appear instantly.
A freight train left Delhi for Mumbai at an average speed of 40 km/hr. Two hours later, an express train left Delhi for Mumbai, following the freight train on a parallel track at an average speed of 60 km/hr. How far from Delhi would the express train meet the freight train?
Answer (c) & explanation
The express meets the freight train 240 km from Delhi (c). Step 1: the freight train has a 2-hour start at 40 km/hr. Its lead = 2 × 40 = 80 km. Step 2: the express is faster by 60 − 40 = 20 km/hr. This is the relative speed. The gap closes in 80 ÷ 20 = 4 hours. Step 3: in 4 hours the express covers 4 × 60 = 240 km. Check: the freight train has run 6 hours × 40 = 240 km. Option (d), 120 km, is the express's distance in 2 hours. Options (a) and (b) do not fit.
Tip: when one vehicle chases another in the same direction, subtract the speeds. The chase time = lead ÷ difference in speed.
Answer as per the official UPSC answer key.
(Same information as the question above.)
Who of the following belongs to Hyderabad?
Answer (b) & explanation
E belongs to Hyderabad (b). Step 1: from the earlier steps, C is from Delhi, D Shillong, F Srinagar, G Chennai and B Kanpur. Step 2: A, the Economics lecturer, is from Mumbai, because A is not from Hyderabad. Step 3: the only city left is Hyderabad, and the only person left is E. Option (a) B is from Kanpur. Option (c) is wrong because E fits. Option (d) fails because the data settle it.
Tip: linked questions in a set usually build on each other. Once you have solved the grid for one question, the next answers follow quickly. Keep your table on the page and do not solve it again.
Answer as per the official UPSC answer key.
Consider the following statements :
- 1. The Factories Act, 1881 was passed with a view to fix the wages of industrial workers and to allow the workers to form trade unions.
- 2. N.M. Lokhande was a pioneer in organizing the labour movement in British India.
Which of the above statements is/are correct ?
Answer (b) & explanation
Only statement 2 is correct (b). Statement 1 is wrong because the Factories Act, 1881, under Lord Ripon, dealt mainly with child labour. It banned work for children under 7 and limited children aged 7–12 to 9 hours a day. It said nothing on wages or trade unions. Statement 2 is right because N. M. Lokhande, a follower of Jyotiba Phule, founded the Bombay Mill Hands Association in 1890, India's first organised labour body. He won a weekly holiday for mill workers.
The 1891 Factories Act went further, limiting women's work to 11 hours. Notice the later milestones: the AITUC (1920, first president Lala Lajpat Rai) and the Trade Unions Act, 1926.
Answer as per the official UPSC answer key.
Consider the following statements :
- 1. In India, the Himalayas are spread over five States only.
- 2. Western Ghats are spread over five States only.
- 3. Pulicat Lake is spread over two States only.
Which of the statements given above is/are correct ?
Answer (b) & explanation
Only statement 3 is correct (b). Statement 1 is wrong because the Indian Himalayas cross many States and UTs, about 12: Jammu & Kashmir, Ladakh, Himachal Pradesh, Uttarakhand, Sikkim, West Bengal (Darjeeling), Arunachal Pradesh, and the northeastern hill ranges. Statement 2 is wrong because the Western Ghats run through six States: Gujarat, Maharashtra, Goa, Karnataka, Kerala and Tamil Nadu. Statement 3 is right because Pulicat Lake, India's second-largest brackish lagoon, lies in Andhra Pradesh and Tamil Nadu only.
Sriharikota, with ISRO's launch centre, separates Pulicat from the sea. Notice that Chilika (Odisha) is the largest lagoon. The Western Ghats are a UNESCO site (2012) and one of the world's biodiversity hotspots.
Answer as per the official UPSC answer key.
In India, if a species of tortoise is declared protected under Schedule I of the Wildlife (Protection) Act, 1972, what does it imply ?
Answer (a) & explanation
Schedule I listing gives the same protection as the tiger (a). Schedule I of the Wildlife (Protection) Act, 1972 gives the highest protection and the heaviest penalties: jail of 3 to 7 years and a fine of at least ₹25,000. Every animal on it gets the same level of protection, whether it is a tiger or a star tortoise. Listing does not mean the animal is extinct in the wild or beyond saving (b). It does not mean it is endemic to one region (c). So (d) is wrong too.
After the 2022 amendment, there are four Schedules: I and II for animals with different levels of protection, III for plants, and IV for CITES species. Notice the protected Indian tortoises, such as the Indian star tortoise and the Travancore tortoise.
Answer as per the official UPSC answer key.
15 students failed in a class of 52. After removing the names of failed students, a merit order list has been prepared in which the position of Ramesh is 22nd from the top. What is his position from the bottom?
Answer (c) & explanation
Ramesh is 16th from the bottom (c). Step 1: 15 of the 52 students failed and were removed. So the merit list has 52 − 15 = 37 names. Step 2: position from bottom = total − position from top + 1. Step 3: = 37 − 22 + 1 = 16th. Option (d), 15th, forgets to add 1. Option (a), 18th, and option (b), 17th, come from using the wrong total or adding wrongly. Check: 21 people above him, 15 below, plus him = 37.
Tip: use the "+1" rule in every rank question: top rank + bottom rank = total + 1. It works because the person is counted in both ranks.
don't use 52; the failed students are not in the list.
Answer as per the official UPSC answer key.
Examine the following statements :
- 1. All colours are pleasant.
- 2. Some colours are pleasant.
- 3. No colour is pleasant.
- 4. Some colours are not pleasant.
Given that statement 4 is true, what can be definitely concluded?
Answer (d) & explanation
Statement 1 is definitely false (d). Step 1: statement 4 says "some colours are not pleasant". Step 2: this is the exact opposite of statement 1, "all colours are pleasant". If some colours are not pleasant, then not all are. So 1 is false. Step 3: statement 2, "some colours are pleasant", could be true or false. Statement 3, "no colour is pleasant", could also be true or false. So options (a), (b) and (c) are not certain.
Tip: learn the opposite pairs: "all are" against "some are not", and "none are" against "some are". If one of a pair is true, the other is false. Other pairs tell you nothing for sure.
Answer as per the official UPSC answer key.
‘Recognition of Prior Learning Scheme’ is sometimes mentioned in the news with reference to
Answer (a) & explanation
RPL certifies skills learnt through traditional channels, such as by construction workers (a). Recognition of Prior Learning is a part of PMKVY under the Skill India Mission. It assesses and certifies skills people picked up informally on the job, such as masons, carpenters, plumbers and electricians, using NSQF standards. The certificate improves their pay and job mobility. It is not about university distance learning (b). It does not reserve jobs in PSUs (c). It does not certify trainees from formal courses (d), whose certification is the main short-term training track.
The Ministry of Skill Development runs it through the NSDC and Sector Skill Councils. Notice how it fits PM Vishwakarma (2023), which also helps traditional artisans with training and credit.
Answer as per the official UPSC answer key.
According to the Wildlife (Protection) Act, 1972, which of the following animals cannot be hunted by any person except under some provisions provided by law ?
- 1. Gharial
- 2. Indian wild ass
- 3. Wild buffalo
Select the correct answer using the code given below :
Answer (d) & explanation
All three cannot be hunted except as the law allows (d). Section 9 of the Wildlife (Protection) Act, 1972 bans hunting any wild animal listed in the Schedules. The exceptions are narrow, such as an animal that has become dangerous to human life (Section 11), or for research and education with permission (Section 12). The gharial (1), Indian wild ass (2) and wild buffalo (3) are all Schedule I species, with the highest protection.
The 2022 amendment cut the Schedules from six to four and brought in CITES listings. Notice where these animals live: the gharial in the Chambal, the wild ass only in the Little Rann of Kutch, and the wild buffalo in Assam and Chhattisgarh, where it is the State animal.
Answer as per the official UPSC answer key.
Consider the following pairs :
| Traditions | Communities
| 1. Chaliha Sahib Festival | Sindhis
| 2. Nanda Raj Jaat Yatra | Gonds
| 3. Wari-Warkari | Santhals
Which of the pairs given above is/are correctly matched ?
Answer (a) & explanation
Only pair 1 is correct (a). Chaliha Sahib is a 40-day fast and prayer by Sindhis to Jhulelal, their patron saint, held each July–August (1). Pair 2 is wrong because the Nanda Devi Raj Jat is a pilgrimage held about every 12 years in the Garhwal–Kumaon hills of Uttarakhand. It escorts Goddess Nanda to Homkund and has no connection with the Gonds of central India. Pair 3 is wrong because the Wari is the Warkari foot-pilgrimage to Vitthala (Vithoba) at Pandharpur, Maharashtra, carrying the palkhis of saints Dnyaneshwar and Tukaram. It has nothing to do with the Santhals.
Notice the Santhal festivals to keep apart: Sohrai and Karam. The Santhal rebellion was the Hul of 1855.
Answer as per the official UPSC answer key.
The painting of Bodhisattva Padmapani is one of the most famous and oft-illustrated paintings at
Answer (a) & explanation
The Padmapani painting is at Ajanta (a). The Bodhisattva Padmapani, a lotus-holding form of Avalokiteshvara, is in Ajanta Cave 1. It was painted in the late 5th century under the Vakatakas, beside the Vajrapani on the back wall of the hall. Its lowered eyes, gentle posture and soft shading make it the best-known image of Indian mural art. Badami (b) has Chalukyan cave paintings. Bagh (c), in MP, has Buddhist murals similar to Ajanta's. Ellora (d) is mainly famous for sculpture, such as the Kailasa temple.
Ajanta's murals use the tempera method on dry plaster. Notice the other famous Ajanta scenes: the Dying Princess (Cave 16) and the Jataka tales.
Answer as per the official UPSC answer key.
In a group of six women, there are four tennis players, four postgraduates in Sociology, one postgraduate in Commerce and three bank employees. Vimala and Kamla are the bank employees while Amala and Komala are unemployed. Komala and Nirmala are among the tennis players. Amala, Kamla, Komala and Nirmala are postgraduates in Sociology of whom two are bank employees. If Shyamala is a postgraduate in Commerce, who among the following is both a tennis player and a bank employee?
Answer (c) & explanation
Nirmala is both a tennis player and a bank employee (c). Step 1: Amala, Kamla, Komala and Nirmala are the four Sociology postgraduates, and two of them are bank employees. Step 2: Amala and Komala are unemployed. So the two bank employees among them are Kamla and Nirmala. Step 3: Komala and Nirmala are tennis players. So Nirmala is both a tennis player and a bank employee. Option (a) Amala and option (b) Komala are unemployed. Option (d) Shyamala is the Commerce postgraduate, and nothing makes her both.
Tip: in group puzzles, use the "unemployed" or "not" clues to rule people out first. The right person is then the one left in both groups.
Answer as per the official UPSC answer key.
Read the passage
An air quality index (AQI) is a way to combine measurements of multiple air pollutants into a single number or rating. This index is ideally kept constantly updated and available in different places. The AQI is most useful when lots of pollution data are being gathered and when pollution levels are normally, but not always, low. In such cases, if pollution levels spike for a few days, the public can quickly take preventive action (like staying indoors) in response to an air quality warning. Unfortunately, that is not urban India. Pollution levels in many large Indian cities are so high that they remain well above any health or regulatory standard for large part of the year. If our index stays in the ‘Red/Dangerous’ region day after day, there is not much any one can do, other than getting used to ignoring it.
Which among the following is the most logical and rational inference that can be made from the above passage?
Answer (c) & explanation
The inference is that the air quality index is not helpful to residents of many large cities (c). Step 1: the passage says an index stuck in 'Red' leaves residents nothing to do "other than getting used to ignoring it". So the index is not helping them. That is option (c). Step 2: option (b) says there is absolutely no need for indices anywhere. That goes beyond the large-city point. Step 3: option (a) blames governments, which the passage does not do. Option (d), more awareness in every city, is not the point.
Tip: India's AQI has six bands, from Good to Severe. The passage's point is that a warning that never changes stops being useful.
Answer as per the official UPSC answer key.
In the context of solving pollution problems, what is/are the advantage/advantages of bioremediation technique ?
- 1. It is a technique for cleaning up pollution by enhancing the same biodegradation process that occurs in nature.
- 2. Any contaminant with heavy metals such as cadmium and lead can be readily and completely treated by bioremediation using microorganisms.
- 3. Genetic engineering can be used to create microorganisms specifically designed for bioremediation.
Select the correct answer using the code given below :
Answer (c) & explanation
Statements 1 and 3 are correct (c). Bioremediation uses microbes, fungi or plants to clean up pollution by speeding up the natural biodegradation that happens anyway (1). Genetic engineering can create microbes designed for particular pollutants (3). Ananda Chakrabarty's oil-eating Pseudomonas was the first patented living organism (1980). Statement 2 is wrong because heavy metals like cadmium and lead cannot be broken down. Microbes and plants can only change their form or concentrate them, as in phytoremediation. So "any ... readily and completely" goes too far.
Bioremediation is used after oil spills, and India's TERI developed Oilzapper for this. Notice the related terms: in-situ (on site) and ex-situ (removed) treatment, and bioaugmentation (adding microbes).
"any", "readily" and "completely" in one line is a strong warning sign.
Answer as per the official UPSC answer key.
In the context of India, which one of the following is the correct relationship between Rights and Duties?
Answer (a) & explanation
Rights are correlative with duties (a). My right to life means others have a duty not to harm me, and my freedom of speech carries a duty not to defame others. So rights and duties are two sides of the same coin. Rights cannot exist apart from society (b), because they are social claims recognised by the community. Saying only rights (c) or only duties (d) matter misses this balance.
The 42nd Amendment (1976) added Part IVA (Fundamental Duties) so citizens would see duties alongside rights. Gandhi said that "real rights are a result of performance of duty." Notice that the Supreme Court has said duties can help courts judge whether restrictions on rights are reasonable, as in AIIMS Students' Union (2001).
this answer sits uneasily with 2017 Q36, which says Fundamental Duties are not correlative to legal duties. This one is about rights and duties in general; that one is about Article 51A.
Answer as per the official UPSC answer key.
What is/are the most likely advantages of implementing 'Goods and Services Tax (GST)'?
- 1. It will replace multiple taxes collected by multiple authorities and will thus create a single market in India.
- 2. It will drastically reduce the 'Current Account Deficit' of India and will enable it to increase its foreign exchange reserves.
- 3. It will enormously increase the growth and size of economy of India and will enable it to overtake China in the near future.
Select the correct answer using the code given below :
Answer (a) & explanation
Only statement 1 is correct (a). GST, launched on 1 July 2017 under the 101st Amendment, replaced central excise, service tax, State VAT, entry tax, octroi and other levies with one tax, collected at each stage on the value added. This created a single national market (1). Statements 2 and 3 are exaggerated. GST may help growth a little through efficiency, but "drastically" cutting the current account deficit or helping India overtake China are not results any tax reform can promise.
The GST Council (Article 279A) is chaired by the Union Finance Minister. In September 2025, the "GST 2.0" reform cut the rates to two main slabs, 5% and 18%, plus a 40% rate on sin and luxury goods. Notice the key Supreme Court case: in Mohit Minerals (2022), it said the Council's recommendations are not binding.
words like "drastically", "enormously" and "overtake China". Exaggerated claims are rarely the right answer.
Answer as per the official UPSC answer key.
Read the passage
There is no harm in cultivating habits so long as they are not injurious. Indeed, most of us are little more than bundle of habits. Take away our habits and the residuum would hardly be worth bothering about. We could not get on without them. They simplify the mechanism of life. They enable us to do a multitude of things automatically, which, if we had to give fresh and original thought to them each time, would make existence an impossible confusion.
The author suggests that habits
Answer (c) & explanation
The author suggests that habits make it easier for us to live (c). Step 1: the passage says habits "simplify the mechanism of life" and save us from "an impossible confusion". So habits make daily life easier. That is option (c). Step 2: option (a), that habits make life difficult, is the opposite. Step 3: option (d) says habits mechanise our lives. The passage says habits work "automatically", but it means they free us, not that they make us machines. Option (b), adding precision, is not the author's point.
Tip: do not confuse a word in the passage, like "mechanism", with the option built from it. Match the meaning, not just the word.
Answer as per the official UPSC answer key.
In a test, Randhir obtained more marks than the total marks obtained by Kunal and Debu. The total marks obtained by Kunal and Shankar are more than those of Randhir. Sonal obtained more marks than Shankar. Neha obtained more marks than Randhir. Who amongst them obtained highest marks?
Answer (d) & explanation
The data are inadequate (d). Step 1: Randhir scored more than Kunal and Debu combined. Neha scored more than Randhir. Step 2: Sonal scored more than Shankar. Kunal and Shankar together beat Randhir. Step 3: nothing compares Neha with Sonal. Neha beats Randhir, and Sonal beats Shankar, but Sonal could be above or below Neha. So the top scorer cannot be found. Option (a), Randhir, is beaten by Neha. Options (b) Neha and (c) Sonal are both possible but not certain.
Tip: before naming a "highest", make sure one person is linked above everyone. Two separate chains with no link between their tops mean the data are not enough.
Answer as per the official UPSC answer key.
In a school, there are five teachers A, B, C, D and E. A and B teach Hindi and English. C and B teach English and Geography. D and A teach Mathematics and Hindi. E and B teach History and French. Who teaches maximum number of subjects?
Answer (b) & explanation
B teaches the most subjects (b). Step 1: list each teacher's subjects. B appears in three pairs: Hindi and English (with A), English and Geography (with C), and History and French (with E). Step 2: so B teaches Hindi, English, Geography, History and French. That is 5 subjects. Step 3: A teaches Hindi, English and Mathematics, which is 3. D teaches Mathematics and Hindi, which is 2. E teaches History and French, which is 2. C teaches English and Geography. So option (b) is right.
Tip: write each name once and list all the subjects linked to it, without repeats. The person who appears in the most pairs usually has the most subjects.
Answer as per the official UPSC answer key.
In the context of mitigating the impending global warming due to anthropogenic emissions of carbon dioxide, which of the following can be the potential sites for carbon sequestration ?
- 1. Abandoned and uneconomic coal seams
- 2. Depleted oil and gas reservoirs
- 3. Subterranean deep saline formations
Select the correct answer using the code given below :
Answer (d) & explanation
All three are possible storage sites (d). Geological carbon sequestration, part of CCS (carbon capture and storage), pumps CO₂ deep underground. Unmineable coal seams absorb CO₂ onto the coal and can release methane in exchange, a method called ECBM (1). Depleted oil and gas fields once held gas safely for millions of years, and injecting CO₂ can also push out leftover oil (enhanced oil recovery) (2). Deep saline aquifers have the largest storage capacity of all (3).
Norway's Sleipner project has stored CO₂ in a saline formation since 1996. Notice India's steps: NITI Aayog's CCUS report (2022) and ONGC's EOR trials. Remember the other carbon sinks too: oceans, forests and soils.
Answer as per the official UPSC answer key.