Blood Relation Reasoning
Blood relation does mean biological relation. Remember a wife and husband are not biologically related but they are biological parents of their own children. Similarly, brother, sister, paternal grandfather, paternal grandmother maternal grandfather, maternal grandmother, grandson, granddaughter, niece, cousin, etc. are our blood relatives.
Types of Questions
Questions based on Relationship of a Family
Example 1: A has 3 children. B is the brother of C and C is the sister of D, E who is the wife of A is the mother of D. There is only one daughter of the husband of E. What is the relation between D and B?
- Brother
- Sister
- Daughter
- Son
Solution (1): Brother
With the chart
Therefore, D is a boy because there is only one daughter of E.
Hence, B is the brother of D.
Note: While solving the question (+) can be used for male and (-) can be used for female.
Questions based on Coded Relation
When the relation between two persons is represented by codes or symbols like +, –, ×, ÷, etc then we say they have a coded relation.
Example 2: If ‘A + B’ means A is the mother of B; ‘A × B’ means A is the father of B; ‘A $ B’ means A is the brother of B; and ‘A @ B’ means A is the sister of B, then which of the following means P is the son of Q?
- Q + R @ P @ N
- Q + R $ P @ N
- Q × R $ P @ N
- Q + R $ P $ N
Solution (4): Q + R $ P $ N
- Q + R = Q is the mother of R
- R $ P = R is the brother of P
- P $ N = P is the brother of N
Therefore P is the son of Q.
Questions based on Indirect Statements
Example 3: Pointing to a photograph, Rekha says to Lalli, “The girl in the photo is the second daughter of the wife of the only son of the grandmother of my younger sister.” How this girl in the photograph is related to Rekha?
- Elder sister
- Younger sister
- Younger daughter
- Elder daughter
Solution (2): Younger Sister
- Grandmother of the younger sister of Rekha ⇒ Grandmother of Rekha
- Wife of the only son of grandmother ⇒ Mother of Rekha
- Second (younger) daughter of the mother ⇒ Younger sister of Rekha.
Points to Remember
Below are given some indirect relations in the form of a list. Examinees are required to learn them. If this list is kept in mind, he/she will find it very easy to solve problems based on blood relations.
| My mother’s or father’s son | ⇒ my Brother. |
| My mother’s or father’s daughter | ⇒ my Sister. |
| My mother’s or father’s father | ⇒ my Grandfather. |
| My mother’s or father’s sister | ⇒ my Aunt. |
| My mother’s or father’s brother | ⇒ my Uncle. |
| My son’s wife | ⇒ my daughter-in-law. |
| My daughter’s husband | ⇒ my Son-in-law. |
| My brother’s son | ⇒ my Nephew. |
| My brother’s daughter | ⇒ my Niece. |
| My sister’s husband | ⇒ my brother-in-law. |
| My brother’s wife | ⇒ my Sister-in-law. |
| My husband’s or wife’s sister | ⇒ my Sister-in-law. |
| My husband’s or wife’s brother | ⇒ my Brother-in-law. |
| My uncle’s or aunt’s son or daughter | ⇒ my Cousin. |
| My wife’s father or husband’s father | ⇒ my Father-in-law. |
| My wife’s mother or husband’s mother | ⇒ my Mother-in-law. |
| My father’s wife | ⇒ my Mother. |
| My mother’s husband | ⇒ my Father. |
| My son’s or daughter’s son | ⇒ my Grandson. |
| My son’s or daughter’s daughter | ⇒ my Granddaughter. |
| The only son of your father | ⇒ Yourself |
| Wife of the father | ⇒ Mother |
| The only son of grandfather/mother | ⇒ Father |
| Only daughter-in-law of grandfather/mother | ⇒ Mother |
| Mother-in-law of mother | ⇒ Grandmother |
| Father-in-law of mother | ⇒ Grandfather |
| The only daughter of the father | ⇒ Sister |
| Son of the father of the sister | ⇒ Brother |
| Son of the only son of the father | ⇒ Son |
| Son of the only son of grandfather | ⇒ Brother |
| Daughter of the only son of Grandfather | ⇒ Sister |
Solved Examples
Example 4. P is the brother of Q. M is the sister of Q. T is the brother of P. How is Q related to T?
- Brother
- Sister
- Brother or Sister
- Data inadequate
Solution (3): Brother or Sister
T and P are the brothers of Q.
Gender of Q is not given. Hence, Q is either brother or sister of T.
Example 5. Pointing to a boy, Seema said “He is the son of my grandfather’s only child”. How is the boy related to Seema?
- Brother
- Cousin
- Sister
- Data inadequate
Solution (1): Brother
The only child of Seema’s Grandfather means Seema’s mother or Seema’s father.
Hence, that boy is Seema’s brother.
Example 6. If ‘A×B’ means B is the father of A; ‘A+B’ means A is the wife of B; and ‘A ÷ B’ means A is the brother of B; then, what is the relation of J with L in ‘J+H÷R×L’?
- Daughter
- Daughter-in-law
- Sister-in-law
- Cannot be determined
Solution (2): Daughter-in-law
J is R’s brother’s wife. L is the father of H and R.
∴ J is the daughter-in-law of L.
Example 7. A introduces B saying, “He is the husband of the granddaughter of the father of my father”. How is B related to A?
- Brother-in-law
- Sister-in-law
- Son-in-law
- Daughter-in-law
Solution (1): Brother-in-law
Father of the father means grandfather, Granddaughter of the grandfather means sister. Husband of the sister means brother-in-law.
So, B is A’s brother-in-law.
Example 8. Pointing towards a person in a photograph, Anjali said, “He is the only son of the father of my sister’s brother.” How is that person related to Anjali?
- Uncle
- Brother
- Cousin
- Son
Solution (2): Brother
- Sister’s Brother → Brother
- Brother’s father → Father
- Father’s son → Brother
∴ The person in the photograph is Anjali’s brother.
Example 9. A and B are brothers. C and D are sisters. A’s son is D’s brother. How is B related to C?
- Brother
- Father
- Uncle
- Cousin
Solution (3): Uncle
- Here B is the brother of A,
- A’s son is D’s brother.
- So, D is the daughter of A.
- Since C and D are sisters and C is also the daughter of A.
∴ B is the uncle of C.
Example 10. A, B, C, D, E, F and G are members of a family consisting of four adults and three children, two of whom, F and G are girls. A and D are brothers and A is a doctor. E is an engineer married to one of the brothers and has two children. B is married to D and G is their child. Who is C?
Solution: E is married to A or D, But B is married to D.
Thus, E is married to A and A, B, D, E are four adults, and C, F, G are the three children in the family.
B and D have a child G.
A and E have two children, they are C and F.
F and G are only girls. So, C is a boy.
∴ C is the son of A and E.
Example 11. If P + Q means P is the son of Q and P = Q means P is the sister of Q. Then what does P = R + Q mean?
Solution: P = R + Q ⇒
P = R which means P is the sister of R.
R + Q means R is the son of Q.
∴ P is the daughter of Q.
Example 12. X – Z means X is the mother of Z; X × Z means X is the father of Z and X + Z means X is the daughter of Z. Now, if M – N × T + Q, then which of the following is not true?
- T is N’s daughter.
- N is wife of Q.
- M is mother-in-law of Q.
- Q is wife of N.
Solution: M – N × T + Q
⇒ M is the mother of N who is the father of T who is the daughter of Q. So, M is the grandmother of the daughter of Q, i.e., M is the mother-in-law of Q.
∴ (2) is not true.
Example 13. There are six persons playing cricket namely U, V, W, X, Y and Z. U and Y are brothers. Z is the sister of Y. W is the only son of U’s uncle. V and X are the daughters of the brother of W’s father.
(i) How is W related to Z?
(ii) How many male players are there?
(iii) How many female players are there?
(iv) How is X related to U?
Solution:
(i) Z is Y’s sister and hence U’s sister, which means W is also the son of Z’s uncle. So, W is Z’s cousin.
(ii) U and Y are brothers. So U and Y are males. Z is the sister of Y and so Z is female. W is the son so W is male. V and X are daughters, so V and X are female. Thus, there are three males, i.e. U, W and Y.
(iii) There are three females, i.e., V, X and Z.
(iv) X’s father is the brother of W’s father and W’s father is U’s uncle. So, X’s father is also U’s uncle. Thus X is U’s cousin.