This Post is about the detailed solution to UPSC Prelims 2020 CSAT question paper solution in detail.
Q.1 A man walks down the backside of his house straight 25 metres, then turns to the right and walks 50 metres again; then he turns towards left and again walks 25 metres. If his house faces to the East, what is his direction from the starting point?
(a) South-East
(b) South-West
(c) North-East
(d) North-West
Answer: D
Refer the above picture, it clearly indicates that the man is finally standing in the North-West Direction.
Q.2 Two Statements are given followed by two Conclusions:
Statements:
All numbers are divisible by 2.
All numbers are divisible by 3.
Conclusion-I:
All numbers are divisible by 6.
Conclusion-II:
All numbers are divisible by 4.
Which of the above Conclusions logically follows/follow from the two given Statements?
(a) Only Conclusion-I
(b) Only Conclusion-II
(c) Neither Conclusion–I Conclusion-II
(d) Both Conclusion–I and Conclusion-II
Answer: A
The numbers divisible by both 2 and 3 will be divisible by the product of the two numbers i.e. 6.
Example: 18 is divisible by 6 but not by 4. Hence, only conclusion I follow.
Q.3 Two Statements are given followed by two Conclusions:
Statements:
All cats are dogs.
All cats are black.
Conclusion-I:
All dogs are black.
Conclusion-II:
Some dogs are not black.
Which of the above Conclusions
logically follows / follow from the two
given Statements, disregarding
commonly known facts?
(a) Only Conclusion-I
(b) Only Conclusion-II
(c) Neither Conclusion-I nor Conclusion-II
(d) Both Conclusion-I and Conclusion-II
Answer: C
Refer the above Venn Diagram, all dogs are not black.
Note: Since both the statements are universal (Universal statements are statements with word like All, None), the conclusion will always be universal. Hence, Some word can not be the part of the conclusion.
Q.4 Consider the following sequence of numbers:
5 1 4 7 3 9 8 5 7 2 6 3 1 5
8 6 3 8 5 2 2 4 3 4 9 6
How many odd numbers are followed by the odd number in the above sequence?
(a) 5
(b) 6
(c) 7
(d) 8
Answer: b
5 1 4 7 3 9 8 5 7 2 6 3 1 5
8 6 3 8 5 2 2 4 3 4 9 6
Here, there are five pairs of odd number followed by the Odd Number. (51), (7,3), (3,9), (5,7), (3,1), (1,5)
Q.5 A is 16th from the left end in a row of boys and Vis 18th from the right end. G is 11th from A towards the right and 3rd from V towards the right end. How many boys are there in the row?
(a) 40
(b) 41
(c) 42
(d) Cannot be determined due to insufficient data
Answer: B
Q.6 Three Statements SI, S2 and S3 are given below followed by a Question:
S1 : C is younger than D, but older than A and B.
S2 : D is the oldest.
S3 : A is older than B.
Question:
Who among A, B, C and D is the youngest?
Which one of the following is correct in respect of the above Statements and the Question?
(a) SI alone is sufficient to answer the Question.
(b) S1 and S2 together are sufficient to answer the Question.
(c) S2 and S3 together are sufficient to answer the Question.
(d) S1 and S3 together are sufficient to answer the Question.
Answer: D
S1: D>C>(A,B)
S2: D is the oldest
S3: A>B
To get the complete order, you must club S1 and S3, this will conclude D>C>A>B. B is the youngest.
S2 is redundant as S1 already says the same thing.
Q.7 How many integers are there between 1 and 100 which have 4 as a digit but are not divisible by 4?
(a) 5
(b) 11
(c) 12
(d) 13
Answer: C
Here, the numbers must be between 1 and 100, Now the numbers can be either in single digits or in double digits.
Double Digit: (40), (41), (42), (43), (44), (45), (46), (47), (48), (49)
or, (04), (14), (24), (34), (44), (54), (64), (74), (84), (94)
Total Numbers: 20
Divisible by 4: 8
Hence, Numbers not divisible by 4 are (20-8=12)
Q.8 Let x, y be the volumes; m, n be the masses of two metallic cubes P and Q respectively. Each side of Q is two times that of P and mass of Q is two times that of P. Let u = m / x and v = n / y. Which one of the following is correct?
(a) u = 4v
(b) u = 2v
(c) v = u
(d) v = 4u
Answer: A
Step1
x, y: Volume P, Q
m, n: Masses of P, Q
Side of Q=2*Side of P, hence, Volume of Q will be 8 times the volume of P. Hence, y=8x
Mass of Q=2*Mass of P, hence, n=2m
Step2
Now, u=m/x , v=n/y
So, u/v= (m/x)/(n/y)
= my/nx
=(m*8x)/(2m*x)
=4/1
Hence, u=4v
Q.9 The average age of a teacher and three students is 20 years. If all the three students are of same age and the difference between the age of the teacher and each student is 20 years, then what is the age of the teacher?
(a) 25 years
(b) 30 years
(c) 35 years
(d) 45 years
Answer: C
Let, age of teacher is t
Let age of three students is s.
Now, Average age of teacher and three three students will be (t+3s)/4
Hence, (t+3s)/4= 20
or, (s+20+3s)/4=20
or, 4s+20= 80
or, 4s=60
or, s=15
Hence, t=15+20=35
Q.10 A person bought a car and sold it for Rs 3,00,000. If he incurred a loss of 20%, then how much did he spend to buy the car?
(a) Rs 3,60,000
(b) Rs 3,65,000
(c) Rs 3,70,000
(d) Rs 3,75,000
Answer: D
Here, it is important to remember that the Profit and Loss are calculated on the basis of Cost Price.
SP= 300000 (i.e. 3L)
Loss Percentage= ((Cost Price- Selling Price)/Cost Price)*100
or, 20=((CP-3L)/CP)*100
or, 1=((CP-3L)/CP)*5
or, CP=5CP-15L
or, 4CP=15L
or, CP=375000
Q.11 Passage–1
Private investment in general is volatile. Foreign private investment is more volatile because the available investment avenues are significantly greater (i.e., the entire world). Therefore, the responsibility of providing employment cannot be left to Foreign Direct Investment (FDI). The current FDI inflows are (volatile over time and across sectors and regions, which is a necessary consequence of their search for the highest returns. The adverse consequences are unstable employment and an accentuation of income and regional inequalities. A probable positive consequence of foreign investment is the inflow of new technology and its subsequent diffusion. However, the technology diffusion is not at all certain because the existing state of physical and human capital in India may prove inadequate for the diffusion.
With reference to the above passage, the following assumptions have been made:
- Relying on foreign investment in the long run is not an economically sound policy.
- Policies must be undertaken to reduce volatility in foreign private investment.
- Policies must be undertaken to strengthen domestic private investment.
- Public investment should be given priority over private investment.
- Substantial public investment in education and health should be undertaken.
Which of the above assumptions is/are valid?
(a) 1, 2 and 4
(b) 1, 3 and 5
(c) 2, 4 and 5
(d) 3 only
Answer: B
UPSC has introduced passage with the options of ‘assumptions’ from the Prelims Paper of 2019.
In order to solve such questions, you must understand the mindset of the author drafting the Passage.
Lets, apply this process here.
S1: From the first two opening statements, it is clear that the author is quite anxious about the volatile nature of the FDI. He clearly disapproves the reliance on it for economic prosperity of the region. Hence, S1 is the right assumption.
S2: The author agree that FDI inflows are volatile which is a necessary consequence of their search for the highest returns.
So, can the government change such volatility?
No, it can’t! Hence, bringing policies to regulate such funds will have very limited impact. S2 is not the correct assumption.
S3: The prime concern of the author is the volatility of the fund and the private investment less volatile compared to FDI. Hence, private investment needs to be promoted. S is correct assumption.
S4: No, not at all. Author has nowhere mentioned such requirements. S4 is not the right assumption.
S5: Just refer the last statement of the paragraph, it stress the requirement of uplifting the human capital to absorb the emerging technology. S5 is correct.
Q.12 Passage–2
Many opportunities to harness the highly skewed, seasonal and spatial distribution of monsoon flows, which occur in a four-month period from June to September annually, have been lost. Since these few months account for most of the rainfall and consequent freshwater availability, the need for holding rainwater in reservoirs, for subsequently releasing it for use over the year, is a necessity nobody can afford to overlook. Climate change will continue to affect weather conditions and create water shortages and excesses. While millions suffer from droughts and floods, waters in the country’s many rivers flow unutilized, and are discharged into the sea every year.
With reference to the above passage, which of the following could be the most rational and practical implications for India?
- Inter-linking of rivers should be undertaken.
- A network of dams and canals should be built across the country for proper distribution of water.
- Farmers should be provided easy loans for digging bore wells.
- Usage of water for agriculture should be regulated by law.
- Distribution of river water among regions should be regulated by the Union Government.
Select the correct answer using the code
given below.
(a) 1 and 2
(b) 2, 4 and 5
(c) 1, 3 and 4
(d) 2, 3 and 5
Answer: A
S5: Not a correct option, author nowhere talks about the political responsibility. In fact, you should start solving the question from this option. Just eliminate option 5, and two options are gone. You are left with options (a) and (c).
S3: Will more bore wells help in tapping the monsoon water? No it will have opposite impact. So S3 is not a good option.
Now, option (c) is gone. So, we are left with option (a) only.
S1: Refer the last statement of the paragraph, to ensure better availability of water, interlinking of river is a feasible option. S1 is correct.
S2: In order to tap the flowing rainwater, building dams and canals are good options. S2 is correct.
S4: Regulating the usage of water for agriculture will lead to optimum utilization of ground water and will be helpful in ensuring the water availability but the author has nowhere mentioned the necessity of such regulation. S4 is incorrect.
Q.13 Passage–3
People will invest in education whenever they are granted the economic freedom to fully enjoy its benefits. Again, this is for the obvious reason that the return on education increases as the level of economic freedom rises. When people, thanks to lower tax rates, are allowed to retain most of the higher income that they gain from each incremental level of education, it makes eminent sense to invest in education. On the other hand, when the government decides to tax the higher income of educated individuals at even higher rates, it makes very little sense to invest in educating oneself further. The same incentives apply to parents who decide on whether to invest in their children’s education.
With reference to the above passage, the following assumptions have been made:
- Lower tax rates in a country invariably translate into greater investments in higher education.
- Investment in the education of children ensures their economic freedom.
- Economic freedom has a positive impact on building up human capital.
Which of the above assumptions is/are
valid?
(a) 1 only
(b) 2 only
(c) 3 only
(d) 1, 2 and 3
Ans: (c)
S1: Focus on the word invariably, it has generalized the statement. Yes, it is true to some extent but Lower Tax Rate will not always lead to greater investment in higher education.
S2: There is no such guarantee that education ensures their economic freedom. Such assumption has nowhere been mentioned in the passage. Hence, this statement is not an assumption.
S3: The statement is nowhere present in the entire passage but the author has expressed a close association between education and economic returns associated with it. Hence, S3 is a correct assumption.
Q.14 Passage-4
Our urban bodies cannot possibly ensure sustainable delivery of water in our cities unless financing mechanisms are put in place. Water delivery requires heavy investment in collecting it from a natural source, treating it to make it potable, and laying a distribution network of pipes for delivery to the users. It also requires investments in sewerage infrastructure and sewage treatment plants so that the sewers can carry the wastewater to these plants to ensure that no untreated sewage is discharged back into natural water bodies. If our cities were rich enough to meet the entire cost, water could be delivered free. They are not.
What is the most logical and crucial message conveyed by the passage?
(a) Urban local bodies must recover costs through user charges.
(b) Urban local bodies are not efficient enough to meet the water requirements of our cities.
(c) Water shortage in our cities is a perennial problem that cannot be solved.
(d) In view of the water crisis in our cities, there is an urgent need to limit the population of cities by adopting an upper limit of population size.
Answer: B
The passage talks about the problem of water availability in our cities. It does not offer any solution. Hence, option (a) gets eliminated.
Option (c) is not correct as such apprehension has nowhere been specified in the passage.
Option (d): No, such measure has not been suggested.
Option (b): This is the message conveyed by the passage.
Q.15 With reference to the above passage, the following assumptions have been made:
- Rich cities only can ensure sustainable delivery of water.
- Sustainable delivery of water in cities means much more than supplying water to households.
Which of the above assumptions is/are valid?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer: B
Easy question, S1: the author has nowhere mentioned that only rich cities can ensure the sustainable delivery of water.
S2: The second statement of the passage clearly indicates it.
Q.16 Passage–5
In India, agriculture still engages about half of its workforce, and about 85 per cent of its farms are small and marginal. Compared to China and Vietnam, which have experienced fast structural and rural transformation, India’s story is of slow transformation. As a result, poverty reduction in India was at a much slower pace during 1988-2014, compared to China and Vietnam. India’s poverty reduction was slow during 1988-2005, but during 2005-2012, it accelerated dramatically—almost three times faster than during the earlier period. What did India do during this period? Research reveals that the relative price scenario changed significantly (by more than 50%) in favour of agriculture in the wake of rising global prices. This boosted private investments in agriculture by more than 50%. As a result, agri-GDP growth touched 41% during 2007-2012 as against 2.4% during 2002-2007. The net surplus of agr-itrade touched $25 billion in 2013-2014; real farm wages rose by 7% per annum. All this led to unprecedented fall in poverty.
With reference to the above passage, the following assumptions have been made:
- Structural and rural transformation is impossible when farms are mainly small and marginal.
- A good price incentive can trigger investments in agriculture.
- India needs to build value chains for high-value agri-products like livestock and horticulture.
- Higher global prices of agricultural commodities are essential for India’s poverty reduction.
Which of the above assumptions are valid?
(a) 1 and 3
(b) 2 and 4
(c) 2 and 3
(d) 3 and 4
Answer: B
S1: 85 per cent of the Indian farmers comes under small and marginal category, this does not mean that the structural and rural transformation can not take place here. S1 is incorrect assumption.
S2: Private investments have increased as agricultural products attracted higher prices. This has been mentioned in the passage as well. S2 is correct.
S3: Not the correct assumption. There is no mention of horticulture or the livestock.
S4: Correct assumption, this has been the case in the period 2007-12.
Hence, only options 2 and 4 are correct assumption.
Q.17 Which one of the following statements best reflects the critical message of the passage?
(a) India should create large-scale off-farm rural employment to reduce poverty in the near future.
(b) India should create a large number of farmer producer companies.
(c) Private investment in agriculture should be given priority over public investment.
(d) Inclusive agricultural growth is key to reduce poverty in the near future.
Ans: (d)
Passage do not talk about the necessity of off the farm employment. Option (a) is incorrect.
The solution to creation farm producer company is not the solution enumerated in the passage. S2 is incorrect.
S3: NO, such comparison has not been made.
S4: Yes, this is correct. To reduce the headcount under poverty, inclusive development is the key.
Q.18