UPSC CSAT Practice Set 10
—Mudit Gupta
QUESTION #1
Sustainable development necessitates a fundamental re-evaluation of traditional growth models, particularly in light of their environmental impact and the equitable distribution of resources among marginalized communities. In today’s world, where resource constraints are increasingly evident, it is imperative to transition from resource-intensive and energy-heavy processes to more efficient and environmentally conscious strategies. Failure to do so risks not only economic stagnation but also the exacerbation of social inequalities, where only a privileged few enjoy prosperity while the majority remain trapped in poverty.
The challenge lies in balancing economic growth with environmental preservation. High environmental standards are no longer optional but are essential for ensuring long-term, inclusive, and equitable development. This approach requires innovative policies that prioritize resource efficiency, renewable energy, and sustainable practices, ensuring that growth benefits all sections of society without compromising the planet’s ecological balance.
Which of the following statements best encapsulates the central idea of the passage?
(a) Economic growth and environmental sustainability are mutually exclusive objectives in the context of developing nations.
(b) The pursuit of rapid economic growth inevitably leads to environmental degradation and social inequality.
(c) Sustainable development requires integrating environmental considerations into growth strategies to ensure inclusivity and long-term prosperity.
(d) Environmental conservation is a luxury that only affluent societies can afford, while developing nations must prioritize economic growth.
Explanation:
The paragraph captures the essence that developmental needs and environmental needs go hand-in-hand to ensure that inequalities are reduced and the environment can be safeguarded.
Option a is incorrect because it says that economic and environmental needs are mutually exclusive. Rather, they are interconnected to each other, as per the paragraph.
Option b is also incorrect as it says that rapid economic growth is bound to bring environmental degradation and inequalities. However, the paragraph says that such economic models should be followed so that the economic growth balances environment and eliminated inequalities.
Option c is correct and captures the essence of the passage.
Option d is incorrect because environmental protection and conservation is not a luxury rather, it is a necessity.
Therefore, (c) is the correct answer.
QUESTION #2
To fit the question mark, the correct answer is:
Explanation:
In such type of question, to find out the answer, let us move element by element, i.e. considering only one shape at a time and not considering all the shapes together.
First of all, let us focus on the black circle. In step 1, the black dot was towards the left; then, in step 2, it moved towards the bottom, and in step 3, it moved towards the right-hand side. In step 4, the black circle again moved to the left-hand side. The pattern has been established clearly that in step 5, the black circle will come to the bottom. Hence, option b and option d are eliminated because the black dot is not at the bottom in those figures. We are left with option a and option c.
Focusing on the small triangle, we can identify that the vertex of the triangle is pointing upwards and downwards alternatively in the figures. In step 5, we want a triangle that is pointing upwards, and hence, option c is eliminated, and the answer is option a.
Therefore, (a) is the correct answer.
QUESTION #3
3 digits are randomly chosen from 1, 2, 3, 4, 5, 6, 7, 8 and 9 without repeating any digit. What is the probability that their product is odd?
(a) 2/3
(b) 5/108
(c) 5/42
(d) 7/48
Explanation:
We have to choose three digits from the nine digits so that the product of all the chosen digits is odd. The odd product of three digits is only possible if all the three chosen digits are odd. Also, none of the digits can be repeated.
In the question given above, first of all let us find out the total favourable outcomes.
Total Favourable Outcomes = 5C3
A few pointers need attention here:
- We need to select three odd digits from the given 5 odd digits viz: 1, 3, 5, 7, and 9.
- We have used combinations here because the order of selection of digits won’t impact the nature of the product of the digits.
On similar grounds, the total possible outcomes become:
Total Possible Outcomes = 9C3
Out of the nine digits given to us, we have to select any three digits and the order of selection is not important and hence, we have used combinations here.
Probability = 5C3/9C3 = 5/42
Therefore, (c) is the correct answer.
QUESTION #4
Please note: In the question given below, x raised to the power of n is written as x^n
32 ^ 5 + 2 ^ 27 is divisible by
(a) 3
(b) 7
(c) 10
(d) 11
Explanation:
This is PYQ from UPSC CSE 2024.
There are 2 steps in which this question can be solved.
Step 1: Find out the unit digit of the entire expression. If the unit digit comes out to be 0, the entire expression will be divisible by 10.
Step 2: If the unit digit isn’t 0, we will find out the remainder of the expression by dividing by 3, 7, and 11. If the remainder is 0 in any of the cases, the expression will be divisible by that number.
First let us find out the unit digit of the expression given above.
32^5 + 2^27
Since we have to find only the unit digit, let us discard the digits at the tens place. So, the expression becomes: 2^5 + 2^27
The cyclicity of 2 is 4. So, we can divide the powers of 2 by 4 and raise the respective remainders as the new powers.
The above equation, after applying the concept of cyclicity, becomes: 2^1 + 2^3
Solving the expression we get: 2+8 = 10 i.e. the unit digit is 0.
Since the unit digit of the above expression is 0, it is divisible by 10.
Therefore, (c) is the correct answer.
QUESTION #5
Find the number of zeroes at the end of the product of the expression:
(a) 25
(b) 36
(c) 42
(d) 56
Explanation:
Please note: In the question given below, x raised to the power of n is written as x^n
To find the number of zeroes in any expression, we must find the number of pairs of 2 and 5.
First, let us combine all the powers of 2 and 5. Combining the powers of 2 we get 2^36, and combining all the powers of 5, we get 5^42.
Since the power of 2 is less than the power of 5, we can only form 36 pairs of 2 and 5 i.e. we can only have 36 zeroes at the end of the above given expression.
Therefore, (b) is the correct answer.
(About our Expert: Mudit Gupta has been a mentor and faculty for the UPSC Civil Services exam for 8 years with expertise in CSAT, Polity, International Relations, and Current Affairs. He is known to break complex concepts into simpler ones that allow UPSC aspirants to develop a grip over the subject matter.)
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A solid strategy, a smart approach, and consistent practice are the keys to success in your CSAT preparation. Here’s Practice Set 10 for your regular practice. 
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