புதன், 27 ஜனவரி, 2016

Reasoning Blood Relations

Reasoning Blood Relations Topic Shortcuts Complete Explanation [How to Solve]

Blood Relationships Tips with Examples:
Hi friends Blood Relations is one of the most common topic that everyone gets confused very often. It is also a guarantee question in every competitive exam recently so we tried to explain it here in detailed manner with examples try to follow them. Normally the questions on blood relations express a lengthy complicated relation for a short, simple and direct relation. So in order to solve these type questions, the students should be thorough with blood relations and also be in a position to relate the people by analyzing the given statements.

The relationship can be shown by drawing a 'Family Tree'. The important aspect is that the diagram should always clearly depict the 'Generation' and reflect the 'Gender'. Hence, 'Horizontal lines' are drawn to indicate marriage; vertical lines indicate children, broken lines for sibling relationship and for the gender, we can use 'm' for male and 'f' for 'female' and 'x' for unknown.
Some generally used notations or symbols:
_____       = marriage relationship
- - - - -      = sibling relationship
| or / or \   = children
m = male, M = mother
f = female, F = father.

Note: You can use what ever notations you think easy for you but stick to them and practice so that you can do it fast during exams.

Actually questions on Blood relations can be asked in three types as follows:
  1. Identification model.
  2. Introduction model.
  3. Symbolic relation model.
We will now see them in details with examples
1. Identification model:
For Example Rajesh is brother of Barath. Barath is brother of Shiva. How is Shiva related to Rajesh?
Here by using the notations above
Rajesh(m) ------- Barath (m) ------ Shiva(x).
In the given question Shiva's gender is not given. Hence, Shiva can be brother or sister of Rajesh. It is very important to note that the gender of the person cannot be decided based on the name of the person. The given data should adequately support the gender of the person.

2. Introduction model:
For Example Pointing to a person, Harsha said, "He is the son of my grandfather's only child". How the person is related to Harsha?
Harsha's grandfather's only child should be Harsha's father or mother. So, the person is Brother of Harsha. In order to solve these kind of questions it is important to note some of the following statements that we normally come across while solving the questions:
  • My mother's only child means myself.
  • My husband's father-in-law's only daughter means myself.
  • My brother's father's wife means my mother.
  • My father's brother's only sibling is my father.
  • My father's mother's only child means my father.
3. Symbolic relation model: (Important)
For Example if
'A × B' means 'A is mother of B';
'A ÷ B' means 'A is son of B'
'A + B' means 'A is husband of B';
'A − B' means 'A is sister of B'.
Which of the following expressions indicate G is daughter of H?
1) G − R ÷ H
2) G + R − H
3) R ÷ G ÷ H
4) H × R − G
5) G + R + H
Now let us discuss this in step by step process
It can be expanded as follows:
G − R; R ÷ H
G − R represents G is sister of R
R ÷ H represents R is son of H.
By combining both the expressions:

Clearly, G is daughter of H.
But, students are always advised to eliminate the options that are not matching based on the gender. In the given question it is clear that G is a female.
Now, observe option (2) G + R − H.
Here, G +R indicates G is husband of R. Hence, it can be eliminated.
Option (3) R ÷ G ÷ H. Here, G ÷ H indicates G is son of H. In the
Option (4) G's gender is not known.
Finally in option (5) G + R + H, G + R indicate G is husband of R.
So, if the questions are complicated in nature we can arrive at the conclusion by eliminating the options.

Some of the Common Blood Relations comes in handy:
Few others in addition are
Wife's or Husband's mother: Mother-in-law
Wife's or Husband's father: Father-in-law
Grand father's son: Father or Uncle
Grand father's only son: Father
Grand mother's only son: Mother
Daughter's father: Husband
Son's mother: Wife
Grand father's or Grand mother's only daughter-in-law: Mother
Finally few points may be noted while solving the questions:
  • Read the question and try to identify the persons between whom relationship is to be established. (if possible blend yourself in given character so that it will be easy for you to understand)
  • Try to focus on the points which give maximum definite information.
  • While concluding about the relationship between the two persons be careful about the gender of the persons involved as there is a possibility of committing a mistake by assuming the gender of the person which is not given in the data or which cannot be derived from the data.





Thanks to Mr. K.M. Jaya Rao