Staff Selection Commission conducts Combined Graduate Level Exam for the recruitment to the different Group ‘B’ and Group ‘C’ posts. Jagranjosh.com has come up with SSC CGL Exam (Tier-I): Reasoning: Syllogism: Concepts & Free Online Practice Set. Here, we provide concepts along with Free Online Practice Set to make the ease of students in cracking Syllogism questions in exam.
Concepts: Syllogism
Syllogism is mode of thinking in which one reasons from two statements or propositions, called premises to a third statement or a propositions called the conclusion. A premise is a statement that serves as the basis of the argument. Let us see some statements to elaborate the concept.
1. All stars twinkle
In this statement all the stars are twinkles, hence they should come under twinkles. So the representation will be as follows:
S = Stars, T = Twinkle
2. Some stars twinkle.
As in this statement only some stars are twinkles, there should be two intersecting circles. So the representation will be as follows:
The shaded area represents the stars that twinkle. S = Stars, T = Twinkle
3. No stars twinkle
As no stars twinkle, hence these two are independent of each other. So the representation will be as follows:
S = Stars, T = Twinkle
4. Only stars twinkle
In this case only stars twinkle, twinkle will come under stars. Nothing else can twinkle so twinkle will not have anything except starts intersecting with it. So the representation will be as follows:
S = Stars, T = Twinkle
Let us now see some examples to understand this better.
Example 1) Statements: 1. All trees are green.
2. Banyan is a tree.
Solution) We will get the following diagrams from the above two statements.
B = Banyan, T = Tree, G = Green,
As seen from the diagram, if all trees are green and Banyan is a tree. Banyan is included in the set of Greens and must be Green as well.
Example 2) Statements: 1. some professors are serious peoples.
2. All serious people wear spectacles.
Solution) We will get the following diagrams from the above two statements.
Therefore some professors wear spectacles. Here the shaded area represents those professors who wear spectacles
Example 3) Statements: 1. All dogs bark.
2. Tommy barks
Solution) Here, Tommy is another element in the set of barking things and may not be a dog. The diagrammatic representation would be as follows:
However, here we cannot conclude that Tommy is a dog. All we can conclude is that Tommy may or may not be a dog.
