HOW TO SOLVE QUESTIONS ON BLOOD RELATIONS?

This type of problems involves an analysis of certain blood relations and then deriving inferences on the basis of the given information. Some examples of such questions are as follows.

a) Anupam said to Kapil, “That girl playing with hockey is the younger of the two sisters of the son of my father’s wife”. How is the girl playing hockey related to Anupam?

b) Sudha sees a photograph and points at a man in the photograph and says, “His brother’s father is the only son of my grandfather”. How is Sudha related to the man in the photograph?

In such questions the examiners generally try to assess the aptitude of the examinee regarding analyzing various relationships. Since in this case, generally the questions are to be solved by analyzing and visualizing the relationships, it is very much helpful in gauging the examinee’s visualization in a limited time. The best possible technique to solve such questions has been given in the coming pages. If you are not able to decide the relationship, put yourself in the question (in the place of the person who is making the statement) and then try to find the answer. 

Backtracking means starting with the last information and proceeding backwards. For example, if it is given that he is the son of the mother of my grandfather’s daughter, then we proceed with the last information:‘grandfather’s daughter’. Grandfather’s daughter means aunt (sister of father).Now ‘mother of my grandfather’s daughter’ becomes ‘mother of my aunt’. Mother of my aunt is my grandmother. Hence, he is the son of the mother of my grandfather’s daughter becomes ‘son of my grandmother’, which is father or uncle.

Asin the above given question a) Anupam says to Kapil, ‘my father’s wife’, meansmother, her son (either yourself or your brother, his two sisters (means yoursisters), so the girl playing with hockey is Anupam’s sister.

b)Sudha says in the end, only son of my grandfather which means father only, heis the father of a man’s brother means father of Sudha’s brother. So Sudha issister of the man in the photograph.

Letus have some more examples to gain clarity about this idea.

Example No. 1: Pointing to aphotograph, Rajesh said, “she is the mother of my mother’s mother’s daughter”.How is Rajesh related to the woman in the photograph?

Solution: My mother’s mother’sdaughter means either my mother or my mother’s sister. Mother of my mother ormy mother’s sister means my maternal grandmother. Therefore the man is thematernal grandson of the woman in the photograph.

Example No. 2: Pointing to a boy inthe photograph, Minakshi said, “His sister is the only daughter of my father”.How is the boy related to Minakshi’s father?

Solution: My father’s onlydaughter means Minakshi herself. She is the sister of the boy in the photograph.This means the boy is the brother of Minakshi. Therefore he is the son ofMinakshi’s father.

Example No. 3: Introducing Madhuri,Anil said, “She is the wife of my mother’s only son”. How is Madhuri related toAnil?

Solution: My mother’s only sonmeans Anil himself. Now Madhuri is the wife of that person, means she is thewife of Anil.  

Example No. 4: Pointing to Kajol,Ajay said, “Her mother’s only daughter is my mother”. How is Ajay related toKajol?

Solution: Here in this statementAjay’s mother is the only daughter of his maternal grandmother.

Hismaternal grandmother is the mother of Kajol (because Ajay points to Kajol andsays her mother - means Kajol is Ajay’s mother.

Example No. 5: Rahul said to Raveena,“Your only brother’s sister is my mother”. How Raveena is related to Rahul’smaternal grandmother?

Solution: Here the statementends with my mother, means Rahul’s mother and she is the sister of Rahul’smaternal uncle (mama) and he is the only brother of Raveena, means eitherRaveena is Rahul’s mother or maternal aunt (maasi).Now the question is how Raveena is related to Rahul’s maternal grandmother. Itcan be clearly identified that she is the daughter of Rahul’s maternalgrandmother.

Note: Unless otherwise mentioned, all blood relationsare to be taken from the paternal (father’s) point of view i.e. if grandfatherhas been mentioned it would be taken as father’s father and not as mother’sfather unless maternal grandfather is mentioned.

Thistechnique of backtracking is applied in such questions where a single statementis given. But sometimes there are questions in which the information isprovided in the form of points. Then it is advisable to arrange the informationin the form of a family tree.

 The following rules can be kept inmind, to solve the questions relating to relation in an easy way.

a)  Verticalor diagonal lines should be used to represent parent-child relationships i.e.if the generations are different, these should be represented vertically.

b)  Ifthe relationship is of the same generation, it should be representedhorizontally.

c)  Asingle arrow should be used to mark a relationship of brother or sister i.e.

d)  Adouble horizontal line (like Û) should be used to represent marriages.

e)  Puta + sign before someone who is a male and a – sign before someone who is afemale.

f)   Wheneversomething is not known put a ? mark or some such symbol before it.

Here is an illustration:

Theabove example tells us that:

(i)    Y and Z are a couple; Yis the husband while Z is the wife.

(ii)    Y has a sister X.

(iii)    The couple, Y and Z, hasthree children: T, P and another son, whose name is not known. P is also sonwhile the sex of T is not known.

(iv)    T and the other unknownson are unmarried while P is married to Q.

(v)     The couple, P & Q,has a daughter J and a son whose name is not known.

Given the process, how to solve such questionsquickly?

1.   Read the informationgiven quickly, it will give you the idea of the problem.

2.   Use the actualinformation given to make a family tree. It is better to start from therelation of a single degree i.e. no third person is involved in that. Therelation should be a direct one, instead of taking uncle and nephew, it isbetter to take father and son or brother and sister.

3.   When you start making thetree, try to attach the further information given to the tree already madeonly.

4.   Then combined all theinformation and answer the questions accordingly.

Example No. 6: P is brother of Q, R is sister of Q. How P isrelated to R?

Solution:

Itcan be clearly seen that P is the brother of R.

Example No. 7: X and Y are brothers.C and D are sisters. A’s son is D’s brother. How is Y related to C?

Solution: It has been clearlyindicated that Y is the brother of X, X’s son is D’s brother. This implies thatD is the daughter of X. Since C and D are sisters, C is also the daughter of X.So Y is the uncle of C.

Example No. 8: M and N are a marriedcouple. O and P are brothers. O is the brother of M. How is P related to N?

Solution: Mand N are husband and wife. Since O and P are brothers, and O is the brother ofM, P is also the brother of M.Thus, P is the brother-in-law of N.

Example No. 9: A family consists of 5members P, Q, R, S and T. The last one (T) has two sons, an unmarried daughterand a daughter in law. P is the brother-in-law of the above mentioneddaughter-in-law. Q’s sister is not happy with Q’s wife. But P and his fathersupport Q’s wife ‘S’. Who is the daughter of T?

Solution: In this question, ithas been clearly mentioned that T is having 2 sons, 1 daughter and a daughterin law. Now if P is the brother in law of the daughter-in-law of T means P isthe son of T. Secondly if Q’s sister is not happy with Q’s wife implies theother son of T is Q and lastly it has been mentioned that Q’s wife is S. So theonly remaining character is T’s daughter and the only remaining name is R. ThusR is the daughter of T.

Example No. 9(a): What is the relationof P with S?

Solution: Now it has already beenseen that P is the unmarried son of T and S is the daughter-in-law of T. So Pis the brother-in-law of S.

Example No. 9 (b): How is T related to Q?

Solution: It has already been decidedthat T is father of Q.

Example No. 9 {c} : Who is the wife of Q?

Solution: It is clear that thewife of Q is S.

Example No. 10: A is brother of B, Cis the father of A, D is a brother of E, E is a daughter of B. Who is the uncleof D?

Solution: 

It can be seen from the diagram that theuncle of D is A.