Blood Relation Test

Blood Relation problems mainly deal with the hierarchical structure of a family i.e., grand-parents, parents and children etc. Different relationships between the family members of different generations are given. To solve such questions, the entire family tree is to be constructed by plotting out the various relationships.

A blood relation is a very important topic of any Aptitude Test. Such questions may be asked directly or may be given in the form of coded blood relations or data sufficiency questions.

The typical relationships that are commonly used in blood relation problems are summarized below –

Basic Relationships Part I (Must be remembered):

1. Mother's Husband = Father

2. Father's Husband = Mother

3. Father’s or Mother’s son = Brother

4. Father’s or Mother’s daughter = Sister

5. Father’s or Mother’s brother = Uncle

6. Father’s or Mother’s sister = Aunt

7. Father’s or Mother’s father = Grandfather

8. Father’s or Mother’s mother = Grandmother

9. Brother’s or Sister’s Son = Nephew

10. Brother’s or Sister’s Daughter = Niece

11. Uncle’s or Aunt’s son or daughter = Cousin

12. Sister’s Husband = Brother-in-law

13. Brother’s wife = Sister-in-law

14. Son’s wife = Daughter-in-law

15. Daughter’s Husband = Son-in-law

16. Husband’s or wife’s sister = Sister-in-law

17. Husband’s or wife’s Brother = Brother-in-law

Basic Relationships Part II (For Understanding Purpose Only):

1. Grandfather's / Grandmother's only daughter-in-law = Mother

2. The only son of your father = Yourself

3. Your father’s wife = Mother

4. Grandfather's / Grandmother's only son = Father

5. Mother-in-law of mother = Grandmother

6. Father-in-law of mother = Grandfather

7. The only daughter of the father = Sister

8. Son of the only son of the father = Son

9. Son of the only son of the grandfather = Brother

10. Daughter of the only son of grandfather = Sister

Relations from one generation to next:


Generally, the question deals with a hierarchical structure which is based on seven generation three above & three below like this:

Three generations above???

Great grandfather
Maternal great grandfather
Great grandfather-in-law

Great grandmother
Maternal great grandmother
Great grandmother-in-law
Two generations above ??Grandfather
Maternal grandfather
Maternal grandmother
One generations above ?Father, Uncle,
Maternal uncle, Father-in-law
Mother, Aunt
Maternal aunt, Mother-in-law
Current generation(Self) ?Husband, Brother
Cousin, Brother-in-law
Wife, Sister
Cousin, Sister-in-law
One generation below ?Son
Two generations below ??Grandson
Grand daughter
Grand daughter-in-law
Three generations below ???Great grandson
Great grandson-in-law
Great grand daughter
Great grand daughter-in-law

TIPS on cracking Reasoning Questions on Blood Relations

Tip #1: Sound knowledge of blood relations

Father's father ? Grandfather             Mother's father ? Maternal grandfather

Father's mother ? Grandmother         Mother's mother ? Maternal grandmother

Father's brother ? Uncle                    Mother's brother ? Maternal uncle

Father's sister ? Aunt                        Mother's sister ? Aunt

Children of uncle ? Cousin                 Children of maternal uncle ? Cousin

Wife of uncle ? Aunt                          Wife of maternal uncle ? Maternal aunt

Children of aunt ? Cousin                  Husband of aunt ? Uncle

Question: Pointing to a photograph of a boy Suresh said, "He is the son of the only son of my mother." How is Suresh related to that boy?

A. Brother      B. Uncle      C. Cousin       D. Father


Suresh’s mother’s only son is Suresh himself. So, the boy in the photo is Suresh’s son, i.e.

Suresh is the boy’s father. The answer is then D.

Question: If A + B ? A is the mother of B; A - B ? A is the brother B; A % B ? A is the father of B and A x B ? A is the sister of B, which of the following shows that P is the maternal uncle of Q?

A. Q - N + M x P       B. P + S x N – Q  

C. P - M + N x Q       D. Q - S % P


Analyzing the options, we see,

D. Q is the brother of S, S is the father of P ? Q is the uncle of P.

C. P is the brother of M, M is the mother of N, N is the sister of Q ? P is the maternal uncle of Q. Thus, the answer is C.

Tip #2: Draw flowchart when suitable

Question: P is the mother of K; K is the sister of D; D is J’s father. How is P related to J?

A. Mother      B. Grandmother      

C. Aunt         D. Data inadequate



Thus, P is the mother of J’s aunt.

Or, in other words, P is the grandmother of J.

The correct option is B. (The letters beside/under the arrows indicate: m: mother, sis: sister, f: father)

Question: Given, M % N means M is the son of N, M @ N means M is the sister of N and M $ N means M is the father of N. Which of the following shows the relation that C is the granddaughter of E?

A. C % B $ F $ E            B. B $ F $ E % C

C. C @ B % F % E          D. E % B $ F $ C


Analyzing the options, we see,

With Option D:


E is the uncle of C

With Option C:


C is the granddaughter of E.

Hence, the correct option is C.