Syllogism

Syllogism

Syllogism is one of the important topic from competition point of view. Questions from this topic are asked in almost every competetive exams like SSC and PO exams 
 
Syllogism: Also Known as Logical Deduction, It means concluding the results fromm the given statement.

Syllogism Questions can be easily solved by Venn Diagrams.

1. Some/ Few/ x%/ Atleast

Example:
Some Potatoes are Brinjals

2. All/100%

Example:
All Potatoes are Brinjals

3. None/0%

Example:
No Brinjals are Potatoes.
 
 
Rule: Don't conclude anything until you are 100% sure. Don't make assumptions of your own.
 

Examples:

Example 1:

Statements:
1. Some Carrots are Brinjals
2. Some Brinjals are Apples
3. All Apples are Bananas
 
Conclusions:
1. Some Apples are Carrot
2. Some Bananas are Brinjal
3. Some Bananas are Carrot
 
Solution:
 
Note: We have drawn the simplest Venn Diagram for this problems. Other Venn Diagrams are possible.
 
Conclusion:
1. Some Apples are Carrot - From the above venn diagram this conclusion appears to wrong. But We can also draw the below Venn Diagram .
So from the  above two venn diagrams, from first venn diagram this conclusion appears to be wrong and from second it appears to be right. So we are not 100% sure here that why this conclusion is wrong.
 
2. Some Bananas are Brinjal - This conclusion is right, Yes some bananas are brinjals. ( We are 100% Sure here even if we draw other Venn Diagram, this conclusion will always remain true)
3. Some Bananas are Carrot - From the above venn diagram this conclusion is wrong. But We can also draw the below Venn Diagram .
So from the  above two venn diagrams, from first venn diagram this conclusion appears to be wrong and from second it appears to be right. So we are not 100% sure here that why this conclusion is wrong.
 

Example 2:

Statements:
1. All keys are Locks
2. All locks are Bangles
3. All bangles are Cars
 
Conclusions:
1. Some Cars are Locks
2. All Bangles are key
3. Some cars are keys
4. All above conclusions are correct.
 
Solution:
 
From the above diagram, it can be concluded that all the above 3 conclusions are Right

Example 3:

Statements:
1. All fruits are leaves
2. Some leaves are trees
3. No tree is house
 
Conclusions:
1. Some house are fruit
2. Some trees are fruit
3. No house is fruit
4. Either 1 or 3
 
Solution:
 
Conclusion 2: Some trees are fruit is wrong from both above venn diagram. (Here We are not 100% sure whether some trees are fruit or not, Some trees may be fruit but Conclusion is right only when we are 100% Sure)
 
Conclusion 1:  Some house are fruit ( From Venn Diagram 1 this is wrong & From Venn Diagram 2 this is Right. So again we are not 100% sure here, so this conclusion is wrong)
 
Conclusion 3: No house is fruit ( From Venn Diagram 1 this is Right & From Venn Diagram 2 this is Wrong. So again we are not 100% sure here, so this conclusion is wrong)
 
Conclusion 4: Either 1 or 3, this is tricky conclusion. Conclusion 1 says that "Some house are fruit" and Conclusion 2 says that "No house is fruit" both are completely contradictory statements. So one of them must be true (because there is no other option other than these two option). That's why Conclusion "Either 1 or 3" is Right