Blood Relationship and Coded Relationship | Logical Reasoning for CLAT

Introduction

Any relation in the world which either by birth or by marriage is called a Blood Relation.

Example: Any relation by birth will be mother, father, son, daughter, etc. and any relation by marriage will be father-in-law, mother-in-law, etc.

• Questions in Blood Relations are inevitably asked in the examination. The questions are related to our ‘relationships’ in the family. The examiner wants to test your ability to see through the cobweb. It is a test of intelligence and logic. The student is expected to find out the ‘relationship’ between two people based on the given ‘input’.
• Before we proceed further, let us understand clearly that all relationships are an extension of three basic relationships:
• First Basic Relationship is of Parent & Child.
• The second Basic Relationship is of Husband & Wife.
• The third Basic Relationship is of:
  Brother ----- Brother
  or Brother-----Sister
  or Sister-----Sister
• The gender of the persons whose relationship is to be found is also of utmost importance.

Family Tree

To solve the problems in blood relations, one should know how to draw a family tree. A family tree is a pictorial representation of genealogical data.

The following points help in drawing a family tree:

• All the female members of the family are represented by a circle. The name of the person is written inside the circle for convenience.
• All the male members of the family are represented by a square. The name of the person is written inside the square for convenience.
• The relation between two members of the family is shown by connecting a double-headed arrow.
• The spouse relation is represented by the two ends of a double-headed arrow.
• All the family members of the upper generation are represented above in the family tree. Ex: father, mother, uncle, aunt etc. 
• The logic can be extended by representing the grandparents above the parents in the family tree. Ex: grandfather and grandmother.
• All the family members of the same generation are represented in the middle of the family tree. Ex: brothers, Sisters, cousins, wife, husband, etc.
• All the family members of the next generation are represented below in the family tree. Ex: Daughter, son, niece, nephew.

Diagrammatic Representation

• To solve the questions based on Blood relationships, we can represent them diagrammatically as follows:
• This is expressed by one horizontal broken line with gender below it.
  
• We follow this as a standardized system so that there is no room for confusion. Based on the above information, we can describe any relationship diagrammatically.

Types of Blood Relations

• Jumbled relationships
• Relational puzzle
• Coded relations

Type 1: Jumbled Relationships

These are based on direct relationships and the student is expected to see through and find out the exact relationship between the two persons.

Example 1: ‘My father’s only son’.
Solution. It means either the person himself or if the lady is talking to somebody, then she is talking about her brother.

Example 2: When the examiner says, “My son’s mother”.
Solution. It means the person is talking about his wife.

Example 3: A person state that I have no brother or sister and the person in this photograph is son of my father.
Solution. 
So the person is talking about himself & photograph is of his ‘own’.

Example 4: Pointing to a photograph, a person says that this is photograph of only daughter in law of his son’s mother. Whom is he talking about?
Solution. If we follow the statement and draw the diagram as follow:
(Person’s son’s mother is Person’s wife)
Mother’s only ‘Daughter in law’ means that she has only one son and ‘Daughter in law’ is the wife of his own son. The person is talking about. So she is ‘Daughter in law’ of the person as well.

Based on the information given to us, it is possible to solve questions based on Blood Relationships easily in two ways:
(i) Pictorial method
(ii) Analytical method
The student should start with the Pictorial method and after they have clearly understood the pattern, should follow the Analytical method to solve the question quickly or easily.
Table: The following chart will help you to solve questions about blood relationships.

EduRev Tip

• First of all choose the two persons, between whom the relationship is to be established.
• Next, pinpoint the intermediate relationship, i.e., such relationship through which long drawn relationship can be established between the required persons.
• Finally, conclude the relationship directly between the two persons as per the requirement of the question.

Unlike in the previous section, this section will have all the information about the family members in a simple and straightforward manner. The number of family members are more here and many times this section will have a union of two or three families.

One should make use of the family tree to solve the question in the beginning, once the concept is mastered the questions can be answered by looking at information directly.

Example 5: Ravi is a son of Aman’s father’s sister. Sahil is the son of Divya who is the mother of Gaurav and grandmother of Aman. Ashok is the father of Tanya and grandfather of Ravi. Divya is the wife of Ashok.

How is Ravi related to Divya?

(a) Nephew

(b) Son

(c) Grandson

(d) Data inadequate

The correct answer is option (c)

Solution: There is no requirement for drawing a family tree to solve this question. Since Divya is the grandmother of Aman and Aman and Ravi are cousins (from the first statement). Ravi should be a grandson to Divya.

Type 3: Coded Relationship 

• The relationship between the two persons is given in the form of a ‘symbol’. It may be given that A + B means that A is the father of B.
• It tells us that the symbol ‘+’ denotes the relation of ‘father’. But in this statement, it is given that it is A who is the father of B and not vice versa. It does not mean that B is the father of A and nor does it mean that B is the son of A; for we do not know the gender of B. B may be either the son or daughter of A. 
• Similarly, it may be given to us that A + B means that B is the father of A. Again the symbol ‘+’ stands for ‘father’. But here, it is B, who is the father of A and not vice versa.
• Thus, the ‘Coded Relationship’ questions can be categorized into three types:
  (i) Relation of the person on the left with the person on his right.
  (ii) Relation of the person on the right with the person on his left.
  (iii) Mixed coded relationship, i.e. the directions may contain the information wherein both types of cases such as ‘Relation- Back’ and ‘Relation-Forward’ may be given.

Type I (Relation of the person on the left with the person on the right)

• A + B means A is the father of B.
• A – B means A is the mother of B.
• In both these cases, we are given the relationship of A, who is on the left with person B who is on his right. We start from the right and move towards the left. As such, we call it ‘Relation – Back’.

Example 6: If it is given that:

•  ‘A+B’ means ‘A is the father of B’.
•  ‘A – B’ means ‘A is the mother of B'.
• ‘A x B’ means ‘A is the brother of B.’
• ‘A ÷ B’ means ‘A is the sister of B’.

What is the relationship of P with R in the equation: ‘P + Q x R’

The correct answer is P is Father of R. 
Solution. Step 1: (Identification of the TYPE): We note that this is Relation – Back type of case as we are provided with the relation of the person on the left with the person on his right.
Step 2: (Identification of the SYMBOL): We find that the sign ‘x’ between two denotes that the person on the left is the brother of the person on the right. Following the lead, we note that Q is brother of R.
Step 3: Similarly, we can find the relationship between P and Q. The symbol joining them denotes that the person on the ‘left’ is father of the person on the ‘right’ side of the symbol. So P is father of Q.
Step 4: Since P is father of Q and Q is brother of R, therefore P is father of R as well.
What is the relationship of ‘R’ with respect to ‘P’?
We cannot exactly denote the relationship of R with P because we are not given the information with regard to the gender of R. R maybe son of P or maybe is daughter of P. So the exact relationship of P with respect of R cannot be certainly stated.

 Type II (Relation of the person on the right with the person on his left)

• X + Y means Y is the father of  X
• X – Y means Y is the mother of X
• In these cases, we are given the relation of the person on the right with respect to the person on his left. So we move from Left to Right and we call it ‘Relation – Forward’ type.

Example 7: If it is given that:

• ‘A + B’ means ‘B is the father of A’,
  
• ‘A – B’ means, ‘B is the wife of A’,  
  
• ‘A × B’ means ‘B is the  brother of A.’  
  
• ‘A ÷ B’ means ‘B is the daughter of A’.
  What is the relation of U with S in the statement S ÷ T × U?
  (a) U is the son of S
  (b) U is the aunt of S
  (c) S is the aunt of Z  
  (d) S is the mother of U
  The correct answer is option (a)

Solution. Step 1: (Identification of the Type): When we look at the matrix provided to us, we find that it is ‘Relationship –Forward’ type of case since we are provided with the relationship of the person on the right with the person on the left.
Step 2: (Identification of the Symbol) We note that the sign ‘÷’ between the two persons denotes that the person on the right is the daughter of the person on the left. Following this lead, we conclude that T is daughter of S.
Step 3: Next, we note that the sign ‘x’ denotes that the person on the right is the brother of the person on the left side of the symbol. From it, we conclude that in the equation ‘T x U’, U is brother of T.
Step 4:  From Step 2, it is observed that T is daughter of S and from Step 3 we find that U is brother of T, so U is the son of S.
Sometimes, the relationships are given to us in the form of some other symbols as well like ‘D’, or ‘ # ’ or ‘$’ or ‘@’, etc. The format followed to solve the question is the same as discussed above.

Type III (Mixed Coded Relationships)

• The directions may contain information wherein both types of cases such as ‘Relation- Back’ and ‘Relation-Forward’ may be given.

Example 8:
Directions: (Q1-Q2) If it is given that:

• P x Q means Q is mother of P

•  P + Q means P is father of Q

• P – Q means P is brother of Q

• P ÷ Q means Q is sister of P
  Q.1. Which of the following means “M is niece of T”? 
  (a) M ÷ D+ T x R
  (b) T–D+R ÷ M
  (c) T x D + R ÷ M
  (d) M x D + R ÷ T
  The correct answer is option (b) 

  We can also solve these type of questions by options. We observe in the question that the gender of M is female and according to the given statements x and ÷ signs should come before M. So we can check (2) and (3) options.
  (ii) T – D + R ÷ M
  M is a sister of R; D is a father of R; T is a brother of D. So, obviously M is niece of T.

Solved Examples 
Example 9: In a family, there are six members- A, B, C, D, E and F. A and B are a married couple, A being a male member. D is the only son of C, who is the brother of A. E is the sister of D. B is the daughter-in-law of F, whose husband has died.

• How F has related to A?
  (a) Mother
  (b) Sister-in-law
  (c) Sister
  (d) Mother-in-law
  (e) None of these
• How is E related to C? 
  (a) Daughter
  (b) Aunt
  (c) Cousin
  (d) Sister
  (e) Mother
•  Who is C to B? 
  (a) Brother
  (b) Brother-in-law
  (c) Son-in-law
  (d) Nephew
  (e) None of these
• How many male members are there in the family?
  (a) Two
  (b) Three
  (c) Four
  (d) Five
  (e) One

To solve such questions:

• Read the data quickly. This would provide the feel of the problem.
• Separate the actual information, the usually stated information or the negative information.
• Each of the actual information would give you some information that can be used to draw a part of the family tree. It is advisable, to begin with, a sentence that gives information about the parent-child relationship. Grandfather-grandson relationships and brother-sister relationships should be touched on later.
• Go on reading actual information, one by one, and make diagrams for each of the information. These diagrams would be like parts or components of the final family tree. 
• Simultaneously try not to draw additional tree diagrams for each new piece of information that you read. Instead, try adding information to the existing tree diagram on reading the new information. The usually stated information or negative information would be of immense use in this regard.
• Finally, with the help of all given information etc. combine all the components into the final diagram.

Solution. 

• The first sentence is USI while all others are actual information. Since, as suggested above, we should begin with the parent-child relationship. And the third sentence depicts the parent-child relationship, i.e. D is the only son of C who’s a brother of A. Therefore, the diagram is as follows
  
• Now we should look at information that tells more about A, D or C. The second sentence tells us more about A. So, we’ll incorporate that into the diagram.
  
• Now we shall add the leftover information and the one that fits the most in the current diagram is the relationship between D and E. 
  
• We have finally reached in the position of completing our tree diagram by incorporating the final information which is about F who is a female since her husband had died. And B is her daughter-in-law. Therefore, she’s the mother of A and C. 
  
• Since we are done with the family tree, we can easily answer all the above question on the basis of this diagram. 

Example 10: John introduces Mary as the daughter of the only son of my father’s wife. How is Mary related to John?
Solution. 

• Break the given sentence at as.
• Resolving from the last, In the view of John.
• My father’s wife – John's mother.
• Only son of mother – himself, i.e. John.
• Daughter of John – Mary
  So, the correct answer is Mary is John's daughter. 

Note:
Like in the above type of problems From either ends if it is like Father = Father,  Uncle= Uncle, Mother = Mother, Aunt = Aunt….. Then they both may be brothers/sisters /bother & sister depending upon their sex.