Basics of Blood Relation for competitive exams

Basics of Blood Relation

some basic symbols to represent various relations in blood relation questions.

We always use + sign for male.
We always use – sign for female.

• To show the relation from one generation to another (Mother/Father to Son/Daughter), we use single arrow head.
• To show the relation within the same generation (siblings/cousins), we use single arrow head.
• To show the relation between husband & wife, we use double arrow head.

Let us see symbolic representation of various blood relations:
1. A is the father of B: Here we know the gender of A only. B can either be son or daughter.

2. A is the mother of B: Here we know the gender of A only. B can either be son or daughter.

3. B is the son of A: Here we know the gender of B only. A can either be father or mother.

4. B is the daughter of A: Here we know the gender of B only. A can either be father or mother.

5. B is the wife of A: Here we know the gender of both A and B.

6. A is the husband of B: Here we know the gender of both A and B.

7. A is the uncle of C: Here we know the gender of A only. B & C can be either male or female.

8. A is the aunt of C: Here we know the gender of A only. B & C can be either male or female.

9. C is the nephew of A: Here we know the gender of C only. A & B can be either male or female.

10. C is the niece of A: Here we know the gender of C only. A & B can be either male or female.

11. A is the paternal grand-father of C: Here we know the gender of A and B both.

12. A is the paternal grandmother of C: Here we know the gender of A and B both.

13. A is the maternal grandfather of C: Here we know the gender of A and B both.

14. A is the maternal grandmother of C: Here we know the gender of A and B both.

Blood relation questions can be asked in two different ways.

Type I: In this case, the blood relation is not coded.

Direction: M is the mother of B. A is the husband of M. N is the only brother of B. C is married to N. Q is the only child of C. N does not have any sister. J is the father of A.

Solution:
M is the mother of B.

A is the husband of M.

N is the only brother of B.

C is married to N.

Q is the only child of C.

N does not have any sister (Which means B is definitely his brother).

J is the father of A.

Q.1) If A doesn’t have any grandson, then how is Q related to B?

1. Can’t be determined
2. Sister-in-law
3. Daughter-in-law
4. Niece
5. Nephew

Solution: We can see that Q is either the grandson or granddaughter of A. But as per the question, A doesn’t have any grandson which definitely assures that Q is A’s granddaughter. So Q is B’s niece.
Q.2) How is A related to C?

1. Uncle
2. Can’t be determined
3. Father-in-law
4. Nephew
5. Brother-in-law

Solution: A is N’s father and C is N’s wife. So A is the father-in-law of C.
Q.3) How is B related to J?

1. Father
2. Nephew
3. Brother-in-law
4. Brother
5. Grandson

Solution: B is the son of J’s son. So B is the grandson of J.

Type II: In this case, the blood relation is coded.

Directions: Read the following information carefully and answer the question which follows:
‘A*B’ means A is the son of B.
‘A+B’ means A is the father of B.
‘A>B’ means A is the daughter of B.
‘A<B’ means A is the wife of B.
Q.4) What will come in place of the question mark (?), if it is provided that M is the grandmother of F in the expression ‘F*R<S?M’?

1. >
2. <
3. +
4. *
5. Can’t be determined

Solution: F*R means F is the son of R.

R<S means R is the wife of S.

M is the grandmother of F (given already) which means M is either mother of S or R. So we can’t determine the answer for this questions using given options. So the answer is 5.
So we have seen two different ways in which blood relation questions can be asked. Sometimes blood relation concept is used in sitting arrangements as well to make those questions more tough. That application of blood relations will be discussed in basics of sitting arrangement.

Key points related to blood relations:

• Never assume any person to be male or female if not specified in the question.
• Step by step approach can always give the solution for blood relation questions, doesn't matter the question is coded or simple one.