Based on the above passage, the following assumptions have been made:
1. The author of the passage believes that butterflies are creations of Nature’s artistry.
2. The author of the passage believes that the beauty of butterflies is a secondary outcome of their evolutionary adaptations.
Which of the assumptions given above is/are valid?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Explanation:
Assumption 1 is invalid because the passage does not describe butterflies as “Nature’s artistry.” Instead, it emphasises their functional and evolutionary purposes. Assumption 2 is valid because the passage explicitly states that the beauty of butterflies is a “side effect” or secondary outcome of their biological functions.
Therefore, (b) is the correct answer.
QUESTION #2
Consider the question and two statements given below:
Question: Is Z the brother of X?
Statement 1: X is the brother of Y, and Y is the brother of Z.
Statement 2: X, Y, and Z are siblings.
Which one of the following is correct in respect of the Question and the Statements?
(a) Statement 1 alone is sufficient to answer the Question
(b) Statement 2 alone is sufficient to answer the Question
(c) Both Statement 1 and Statement 2 are sufficient to answer the Question
(d) Both Statement 1 and Statement 2 are not sufficient to answer the Question
Explanation:
We have to tell if Z is the brother of X.
Let us consider Statement 1 alone: It says that X is the brother of Y and Y is the brother of Z. We can establish the logic that X, Y, and Z are siblings. However, we cannot tell if Z is the sister of X and Y or the brother of X and Y because the gender of Z is not mentioned in the first statement. Hence, Statement 1 alone is not sufficient to answer the question.
Let us consider Statement 2 alone: It simply says that X, Y, and Z are siblings. However, in this statement as well, the gender of Z is not mentioned. So, we cannot tell if Z is the brother or sister of X, and hence, using both statements together, we cannot answer the question. So Statement 2 alone is not sufficient to answer the question.
If we consider both the statements together, then also we cannot tell if Z is the brother of X or the sister of X. Hence, both the statements taken together are also not sufficient to answer the question.
So, the answer is d, i.e. both the statements are insufficient to answer the question.
Therefore, (d) is the correct answer.
QUESTION #3
Consider two statements and a question:
Statement 1: The last day of the month is Wednesday
Statement 2: The third Saturday of the month was the seventeenth day
Question: What day is the fourteenth of the given month?
Which one of the following is correct in respect of the statements and the Question?
(a) Statement 1 alone is sufficient to answer the Question
(b) Statement 2 alone is sufficient to answer the Question
(c) Both Statement 1 and Statement 2 are required to answer the Question
(d) Neither Statement 1 alone nor Statement 2 alone is sufficient to answer the Question
Explanation:
We have to find the 14th day of the given month.
First of all, let us consider Statement #1 alone:
Statement #1 tells that the last day of the month is Wednesday. However, we don’t know as which month it is talking about. It can be a day with 28 or 29 or 30 or 31 days. And hence, we are not sure about the total number of days in the month so we cannot tell what will be the 14th day of this given month.
Now, let us consider Statement #2 alone.
It says that the 17th of that month was a Saturday. Consequently:
- 16th – Friday
- 15th – Thursday
- 14th – Wednesday
So, using statement 2 alone, we could determine the answer to the question, which is option b.
Therefore, (b) is the correct answer.
QUESTION #4
Following is a matrix of certain entries. The entries follow a certain trend row-wise. Choose the missing entry (?) accordingly.
Explanation:
Such type of questions can be solved by moving in a row-wise manner.
The letters A, B, and C appear once in rows 1 and 2. However, in row 3, A and C are there, but the letter B is missing. So, we need to look for an option with B in it, and hence, the answer can be option A or option C.
The second logic applicable to this question is as follows: The sum of the numbers in the first and the last column is equal to the number in the middle column.
In row #1 7+3 = 10
In row #2 3+6 = 9
So, in row #3 it should be 10+3 =13
Hence, we need numeric 3 in the answer.
Combining logic #1 and logic #2, we get the answer 3B
Therefore, (c) is the correct answer.
QUESTION #5
Please note: In the question given below, x raised to the power of n is written as x^n
Find the unit digit of 3^6 x 4^7 x 6^3 x 7^4 x 8^2 x 9^5
(a) 4
(b) 5
(c) 6
(d) 7
Explanation:
To find the unit digit of the entire expression, we have to find the unit digit of each of the numbers of the expression and then multiply them. To solve this question, we will use the concept of cyclicity.
Therefore, (c) 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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Though qualifying in nature, CSAT can be a real challenge in your Prelims. Therefore, experts advise not to leave it until the last moment. Here’s Practice Set 9 for your regular practice. 
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