Blood Relation Tricks, Examples

 Blood relation does mean biological relation. Remember a wife and husband are met 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.

Below are given some indirect relation in the form of a list. Examinees are required to learn them by heart. If are keeps this list in one’s mind, he/she will find it very easy to solve problems based on blood relations.

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?

Solution: 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 are represented by codes or symbols like +, –, ×, ÷, etc then we say they have coded relation.

Example 2: If A + B means A is the mother of B; A x 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?

  1. Q + R @ P @ N
  2. Q + R $ P @ N
  3. Q x R $ P @ N
  4. Q + R $ P $ N

Solution: (4)

  • 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 of photograph is related to Rekha?


  • Grandmother of younger sister of Rekha is Grandmother of Rekha
  • Wife of only son of grandmother is Mother of Rekha
  • Younger daughter of the mother is Younger sister of Rekha.

Points to Remember

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

1. 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?


(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.

2. P is the brother of Q. M is sister of Q. T is brother of P. How is Q related to T?

  1. Brother
  2. Sister
  3. Brother or Sister
  4. Data inadequate

Solution: (3) T and P are the brothers of Q.

Sex of Q is not given. Hence, Q is either brother or sister of T.

3. Pointing to a boy, Seema said “He is the son of my grandfather’s only child”. How is boy related to Seema?

  1. Brother
  2. Cousin
  3. Sister
  4. Data inadequate

Solution: (1) Only child of Seema’s Grandfather means Seema’s mother or Seema’s father.

Hence, that boy is Seema’s brother.

4. If ‘A × B’ means ‘B is father of A’, ‘A+ B’ means ‘A is wife of B’ and ‘A ÷ B’ means ‘A is brother of B’, then, what is the relation of J with L in ‘J + H ÷ R × L’?

  1. Daughter
  2. Daughter-in-law
  3. Sister-in-law
  4. Cannot be determined

Solution: (2)


J is R’s brother’s wife. L is the father of H and R.

∴ J is daughter-in-law of L.

5. A introduces B saying, “He is the husband of the grand daughter of the father of my father”. How is B related to A?

Solution: Father of the father means grand father, Grand daughter of the grand father means sister. Husband of the sister means brother-in-law.

So, B is A’s brother-in-law.

6. 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?


  • Sister’s brother → Brother
  • Brother’s father → Father
  • Father’s son → Brother

∴  The person in the photograph is Anjali’s brother.

7.  A and B are brothers. C and D are sisters. A’s son is D’s brother. How is B related to C?


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.

8. 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 son of A and E.

9. 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 mean P is the sister of R.

R + Q means R is the son of Q.

∴ P is the daughter of Q.

10. 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?

  1. T is N’s daughter.
  2. N is wife of Q.
  3. M is mother-in-law of Q.
  4. 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.