Ch.11 :- Blood Relations : Introduction & Formula


1. Grandfather’s son Father or uncle.
2. Grandmother’s son Father or uncle
3. Grandfather’s only son Father
4. Grandmother’s only son Father
5. Mother’s or father’s mother Grandmother
6. Mother’s or father’s father Grandfather
7. Grandfather’s only daughter-in-law Mother
8. Grandmother’s only daughter-in-law Mother
9. Mother’s or father’s son Brother
10. Mother’s or father’s daughter Sister
11. Mother’s or father’s brother Uncle
12. Mother’s or father’s sister Aunt
13. Husband’s or wife’s sister Sister-in-law
14. Husband’s or wife’s brother Brother-in-law
15. Son’s wife Daughter-in-law
16. Daughter’s husband Son-in-law
17. Brother’s son Nephew
18. Brother’s daughter Niece
19. Uncle’s or Aunt’s son or daughter Cousin
20. Sister’s husband Brother-in-law
21. Brother’s wife Sister-in-law.
Example 1

Ex.1. pointing to a man in a photograph, a man said to a woman, “His mother is the only daughter of your father.” How is the woman related to the man in the Photograph?
(a) Sister
(b) Mother
(c) Wife
(d) Daughter
(e) Aunt

Sol. From the information given in the question, it is clear that the only daughter of the woman’s father is the Woman herself, and hence the man in the photograph is her son. Therefore, the woman is the mother of the man in the photograph. Therefore, the correct answer is (b).

Example 2

Ex.2. Pointing to a man in a photograph, a woman said, “The father of his brother is the only son of my grandfather.” How is the woman related to the man in the photograph?
(a) Mother
(b) Aunt
(c) Daughter
(d) Sister
(e) Niece

Sol. From the information, it is clear that the only son of woman’s grandfather is the father of the woman and the father of the man’s brother is the father of the man. On combining these two informations together a single information emerges the that the man’s father is the woman’s father. Hence, the worn.” isthe sister of the man in the photograph. Therefore, the correct answer is (d).

Example 3

Ex. 3. Indroducing Asha to guests, Bhaskar said, “Her father is the only son of my father.” How is Asha related to Bhaskar?
(a) Daughter
(b) Mother
(c) Sister
(d) Niece
(e) Aunt

Sol. The only son of Bhaskar’s father is the Bhaskar himself. This means that Bhaskar is the father of Asha. Hence, Asha is the daughter of Bhaskar. Therefore, the correct answer is (a).

Example 4

Ex. 4. Akash said to Mohir, ”That boy in blue shirt is younger of the two brothers of the daughter of my father’s wife.” How is the boy in blue shirt related to Akash.”
(a) Father
(b) Uncle
(c) Brother
(d) Nephew
(e) Grandfather

Sol. The daughter of Akash’s father’s wife is the sister of Akash and brother of the daughter is the brother of Akash. Hence, the boy in blue shirt is the brother of the Akash. Therefore, the correct answer is (c).

Example 5

Ex. 5. ‘S x T’ means that S is the mother of T, ‘S + T’ means that S is the father of T, S – T’ means that S is the sister of T. On the basis of this information, you have to select the option which shows that A is the grandfather of T.
(a) A + S + B- T
(b) A x B + C- T
(c) A + C – T
(d) A + B – C x T
(e) A – C x T

Sol. Option (a) represents that A is the grandfather of T
(i) B- T=> Bis the sister of T.
(ii) S + B=> S is the father of B, hence S will be father of T [from information (i))
(iii) A + S => A is the father of S, hence A will be grandfather of B.

Example 6

Ex. 6. If ‘P $ Q’ means that P is the father of Q, ‘P # Q’ means that P is the mother of Q, ‘P * Q’ means that P is the sister of Q. Then, how is Q related to N in N # L$ P * Q’?
(a) Grand-son
(b) Grand-daughter
(c) Nephew
(d) Data inadequate
(e) None of these

Sol. In the above question, the sex of Q is not given, hence exact relationship between N and Q cannot be established. In other words, we can say that data is not adequate to answer the question. Therefore, the correct answer is (d).

Example 7

Ex. 7. If ‘P + Q’ means that P is the mother of Q, ‘P + Q’ means that P’is ‘the father of Q, ‘P -Q means that P is the sister of Q. Then, which of the following relationship shows that M is the-daughter of R ?
(a) R ÷ M + N
(b) R + N ÷ M
(c) R – M ÷ N
(d) Data inadequate
(e) None of these

Sol . M + N i.e., M is the mother of N, hence, the sex of Mis
determined as female.
R + M i. e., R is the father of M. Hence, R ÷ M + N clearly
means that M is the daughter of R. Therefore, the correct
answer is (a).