Previous Year Topic Wise Questions With Solutions: Blood Relations | CSAT Preparation - UPSC PDF Download

Q1. A question is given followed by two Statements I and II. Consider the Question and the Statements and mark the correct option. 
Question: How is Q related to P? 
Statement I: P has two sisters, R and S. 
Statement II: R’s father is the brother of Q. 
Which one of the following is correct in respect of the above Question and the Statements?   (2025)
(a) The Question can be answered by using one of the Statements alone, but cannot be answered using the other statement alone. 
(b) The Question can be answered by using either Statement alone. 
(c) The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone. 
(d) The Question cannot be answered even using any of the Statements.

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Ans: (d)
Here, we will denote the relations using the following signs:
From statement-I:
From Statement-II:
On combining statements I and II, we get the following family tree:
Here, gender of P and Q is not known. Thus, we cannot determine the unique relationship between P and Q.
Hence, option (d) is the correct answer.

Q2. Consider the following including the Question and the Statements: 
There are 5 members A, B, C, D, E in a family. 
Question: What is the relation of E to B ? 
Statement-1: A and B are a married couple. 
Statement-2: D is the father of C. 
Statement-3: E is D's son. 
Statement-4: A and C are sisters. 
Which one of the following is correct in respect of the above Questions and Statements?    (2023)
(a) Statement-1, Statement-2 and Statement-3 are sufficient to answer the Question. 
(b) Statement-1, Statement-3 and Statement-4 are sufficient to answer the Question. 
(c) All four statement together are sufficient to answer the Question. 
(d) All four statements are not sufficient to answer the Question.

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Ans: (c)
The 5 family members are A, B, C, D, and E. The given statements are:
Statement 1: A and B are a married couple.
Statement 2: D is the father of C.
Statement 3: E is D’s son.
Statement 4: A and C are sisters.
We need to find the relation of E with B.
We must use statements 1 and 3, as B and E have not been mentioned in any other statement.
Option (a): Statements 1, 2 and 3 alone are not sufficient, as we cannot find a link between B and E in these statements.
Option (b): Statements 1, 3 and 4 alone are not sufficient, as we cannot find a link between B and E in these statements.
Option (c): Using all the four statements, we get the following family tree:
So, E is the brother-in-law of B. 
Hence, option (c) is correct.

Q3. Consider the Question and two Statements given below: 
Question: Is Z brother of X? 
Statement-1:" X is a brother of Y and Y is a 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?     (2022)
(a) Statement-1 alone is sufficient to answer the Questions 
(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

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Ans: (d)
Let’s consider the two statements one by one. 
Statement 1: X is the brother of Y, and Y is the brother of Z.

But we do not know whether Z is a male or a female. So, we cannot say whether Z is the brother or sister of X.
Statement 2: X, Y, and Z are siblings. It tells us nothing much. Here, also gender of Z is not known. So, Z can be either brother or sister of X.
Even if we combine the two statements, we cannot answer the given questions.