Practice Questions: Blood Relations - CSAT Preparation - UPSC

Easy Level

These questions are targeted to improve your knowledge of basic concepts, though easy questions are rare in CAT. These are extremely important for conceptual understanding at the foundation level.

Example 1: Pointing to a lady on the stage, Devika said, “She is the sister of the son of the wife of my husband”. How is the lady related to Devika?
(a) Sister-in-law
(b) Sister
(c) Daughter
(d) Cousin
Ans: (c)
Solution: From Devika’s perspective, the wife of my husband means me. Then, my son’s sister means my daughter. Hence, option (c) is correct.

Example 2: Pointing to a lady, a man said, “Her husband is the only son of my mother”. How is the lady related to the man? 
(a) Wife
(b) Daughter
(c) Father-in-law
(d) None of these
Ans: (a)
Solution: Only son of my mother, means me. Hence, the situation transforms into I am her husband. Hence, the lady is the man’s wife. So, the correct option is (a).

Example 3: Pointing to a man, Manisha said, “He is the youngest son of my father-in-law’s only son”. How is Manisha related to this youngest son’s father?
(a) Daughter
(b) Sister
(c) Wife
(d) Can’t be determined
Ans: (c)
Solution: 

• Looking at it from Manisha’s perspective, “my father-in-law’s only son” would be my husband.
• Thus the youngest son of this person would also be Manisha’s son. 
• Hence, this person’s father would be Manisha’s husband, and Manisha would be the wife. Option (c) is the answer.

Medium Level

Almost 70% of questions in CAT are Medium based questions. Though conceptually they seem easier, the trick is to solve the calculations faster & we curated problems for you to help you do problems easier.

Direction: If a + b means a is the daughter of b, a – b means a is the husband of b, a ¥ b means a is the brother of b.
Example 1: What does the relation p ¥ q – r show? 
(a) p is the son-in-law of r
(b) p is the brother of r
(c) r is the wife of p
(d) None of these
Ans: (d)
Solution: p ¥ q – r can be read as p is the brother of q and q is the husband of r. Thus p must be the brother-in-law of r. Hence, option (d) is correct.

Direction: If a + b means a is the daughter of b, a – b means a is the husband of b, a ¥ b means a is the brother of b.
Example 2: Which of the following statements does not hold?
(a) a + b × c
(b) a – b ¥ c
(c) a + b + c
(d) a + b – c
Ans: (b)
Solution: Option (b) says a – b ¥ c, this does not hold since a must be the husband of b (who is a female) and b is the brother of c (which cannot happen). Hence, option (b) is the answer.

Direction: If a + b means a is the daughter of b, a – b means a is the husband of b, a ¥ b means a is the brother of b.
Example 3: From the statement a ¥ b ¥ c ¥ d, which of the following statement is not necessarily true? 
(a) b is the brother of a
(b) c is the brother of a
(c) d is the brother of c
(d) a, b, c are male
Ans: (c)
Solution: 

• a × b ¥ c ¥ d means a is the brother of b, b is the brother of c and c is the brother of d. This makes options (a), (b) and (d) as correct.
• Only option (c) is not necessarily true since d could be b’s sister too.
  Hence, (c) is the answer.

Direction: If a + b means a is the daughter of b, a – b means a is the husband of b, a ¥ b means a is the brother of b.
Example 4: From the statement p – q + r ¥ s, how is q related to s? 
(a) Niece
(b) Sister
(c) Mother
(d) None of these
Ans: (a)
Solution: p – q + r ¥ s reads as p is the husband of q, q is the daughter of r and r is the brother of s. Thus, q must be s’s niece. Hence, option (a) is the correct answer. 

Example 5: Anwar’s father is the only son of Mahesh’s father. How is Mahesh related to Anwar?
(a) Father
(b) Brother
(c) Can’t be determined
(d) None of these
Ans: (a)
Solution: Anwar’s father being the only son of Mahesh’s father, means that Mahesh must be Anwar’s father. Option (a) is the answer. 

Example 6: If 
I. A is the brother of B 
II. B is the brother of C 
III. C is the brother of D 
IV. D is the sister of E. 
Then which of the following statements is not necessarily true?
(a) D is the sister of C
(b) B and C are brothers
(c) A, B, C are male, and D is a female
(d) D and E are sisters
Ans: (d)
Solution: A, B, C are siblings and brothers of each other. D is their sister, but we cannot say anything about E’s sex (whether E is male or female and hence brother or sister is unknown).
Hence, (d) is correct.

Example 7: Pointing to a photograph, Vandana says, “She is the elder daughter of my mother’s husband”. How is a person in the photograph related to Vandana?
(a) Sister
(b) Mother
(c) Sister-in-law
(d) None of these
Ans: (a)
Solution: Sister. Hence, option (a) is the answer. 

Hard Level

Around 25% of these type of questions come in CAT - If your target is above 95%ile, we recommend you solve these questions.

Direction: a * b means a is the brother of b. a @ b means a is the daughter of b. a $ b means a is the sister of b.
Example 1: Which of the following shows the relationship p is the paternal uncle of n?
(a) n$o@p
(b) n@o$p
(c) n@o*p
(d) None of these
Ans: (c)
Solution: n@o*p reads, n is the daughter of o and o is the brother of p. Hence, p becomes n’s, paternal uncle. So, option (c) is correct.

Direction: a * b means a is the brother of b. a @ b means a is the daughter of b. a $ b means a is the sister of b.
Example 2: If a $b$c@d@e*f*g, then how many males and females are there respectively?
(a) 4, 3
(b) 3, 4
(c) 5, 2
(d) Can’t be determined
Ans: (d)
Solution: Again here, g’s sex is indeterminable. Hence, the answer cannot be determined. Option (d) is the answer.

Direction: P, Q, R, S, T went on a picnic. P is the son of Q, but Q is not the father of P. R is the son of S, who is the brother of P. T is the wife of S.
Example 3: How many males are present in this group?
(a) 1
(b) 2
(c) 3
(d) 4
Ans: (c)
Solution: P is the son of Q but Q is not the father of P means that Q must be the mother of P. Also, R is the son of S, who is the brother of P means that S and P must be brothers and R is S’s son. Also, since T is the wife of S, R must be T’s son also. Consolidating these relationships we get: Q mother of S and P (brothers). Also, S’s wife is T and their son is R. P is S’s Brother. Hence, (c) is correct option.