Blood Relations I- Using Logical Reasoning to Understand the Basics

Blood Relation questions are asked in the Logical Reasoning Section of IBPS PO, SSC CGL, SBI PO, SSC CHSL, IBPS Clerk, SBI CLerk and other competitive exams, which makes it mandatory for you to get hold over this topic.

All IBPS PO, SSC CGL, SSC CHSL, SBI PO & other competitive exams have Blood Relation questions in the logical reasoning section which makes it a very important topic. The ideal way to understand any topic in the Logical Reasoning Section of Bank and SSC Exams is to start from the basic and then move ahead. If questions like- If A is the brother of B; B is the sister of C; and C is the father of D, how D is related to A? Confuse you, then this series of blogs on Blood Relation questions is for you where we will start from the basic concepts of logical reasoning and then discuss various methods to solve such logical reasoning questions easily.

Logical Reasoning- Understanding Different Blood Relations

The first step to being able to solve blood relation questions is a logical reasoning of the relations that exist between different members of a family, both close and far. So let’s start right from basic and see what are the different blood relations in a family, which you should know to understand the logical reasoning in blood relation questions.

In-Laws are not a part of your family when you are born. They are people who become a part of your family when marriages happen.

Family Tree- How to use Logical Reasoning to Construct One

Generally, the construction of the family tree is considered to be the most appropriate way of solving blood relation questions from logical reasoning. So let’s see how to construct family trees in blood relation questions, this will make these logical reasoning questions really simple for you. So we start with representing each by gender by a particular sign-

Different Notations that make Logical Reasoning Simple

Now let’s move to the next step in these logical reasoning questions and see how do we denote relations in blood relation questions-

A is the brother of B

We cannot determine the gender of B since B can be either, male or female

A is the sister of B

We cannot determine the gender of B since B can be either, male or female

A is the wife of B

In this case we know the gender of both A and B. We are using a double-sided arrow here to show that the two individuals are married to each other.
If you notice in all the above 3 cases, A and B are in the same generation.
Let’s see how the notation will change when A and B belong to different generations. We start by plotting the tree on different levels, where each level represents a generation in blood relation questions-

A is the son of B

We cannot determine the gender of B since B can be either of the parent, mother or father

A is the mother of B

We cannot determine the gender of B since B can be either of the child, son or daughter

A is the grandfather of B

We cannot determine the gender of A since A can be either of the grandchild, grandson or granddaughter.
The 2 arrows represent that they are 2 generations away.
Do write in the comments below how this blog helped you understand the basics of logical reasoning that you need to know to solve blood relation questions in Bank and SSC Exams.

Stay tuned for the next blog in this series where we will solve statement symbol based blood relation questions.