In this article,we study the "Syllogistic Reasoning". Some formula is given below in details and proper use of the formula to illustrate and make you understand well. Candidates preparing for bank exam (Clerk,PO,SO) and can also download these notes in PDF format.
Syllogisms is one of the easy to win questions in reasoning, but we have seen so many aspirants are finding difficult in solving these questions.Through the use of Venn Diagrams you can solve syllogisms problems in an easy manner.
Main rules to solve Syllogism Problem
- All+Some=No Conclusion
- Some+No= Some Not
- Some+Some= No Conclusion
- No +All = Some Not (Reversed)
- No+Some=Some Not (Reversed)
- No+No=No Conclusion
- Some Not /Some Not Reversed +Anything = No Conclusion
- If the conclusion is in “Possibility” case then these rules must be applied.
- If All A are B then we can say - Some B are Not A is a Possibility
- If Some B are Not A then we can say - All A are B is a Possibility
- If Some A are B then we can say - All A are B is a Possibility All B are A is a Possibility
- All <=> Some Not Reversed
- Some => All
- NO Conclusion = Any Possibility is true
When it is implemented (In case of Conclusion from Single Statement)
- All => Some that means if All A are B then Some B are A is true.
- Some <=> Some that means if Some A are B then Some B are A is true.
- No <=> No that means if No A is B then NO B is A is true
How to solve syllogism problems by syllogism Rules?
There are two ways to solve the problems of syllogism as:-
- Cross Cancellation
- Vertical Cancellation
Example of cross cancellation
- All Cows are Parrots
- All Parrots are Birds
- No Bird is Monkey
- No Parrot is Monkey
- Some Cows being Monkey is Possibility
we can use the Venn diagram method i.e. good but another method is cross cancellation.
Here is explanation
This is called Cross Cancellation , We have cancelled Bird from Bird so we have left with (ALL+NO) rule, and that leads to No Parrot is Monkey So Conclusion I is TRUE.
In second statement we have Cow and Monkey so we will need to make relation between them. For this we need to take all 3 statements.
Now we have left with ((All+All)+NO) that is No Cow is Monkey . We don’t have any rule to convert this statement into Possibility so second conclusion is FALSE
Example of Vertical cancellation
- Some Mails are Messages
- All Updates are Messages
- All Mails Being Update is a Possibility
- No Update is Mail
Lets take Conclusion “All Mails Being Update is a Possibility” that means we have to make relation between Mails and Updates
This is called Vertical cancellation. In this case direction of adding first phrase will be reversed i.e In
Above example the conclusion will be All+Some = No Conclusion.
IF we get No Conclusion in case of Possibility then according to Rules in Possibility case will be definitely true. So Conclusion 1 follows and Conclusion 2nd Don’t.
Questions & Answers
Statements: Some envelops are gums. Some gums are seals. Some seals are adhesives.
- Some envelopes are seals.
- Some gums are adhesives.
- Some adhesives are seals.
- Some adhesives are gums.
A. Only (3)
B. Only (1)
C. Only (2)
D. Only (4)
Statements: Some cars are jeeps.All the boxes are jeeps.All the pens are cars.
- Some cars are boxes.
- No pen is jeep.
- Some boxes are cars.
A. None of three
B. Only (1) and (2)
C. Only (1) and (3)
D. Only (2) and (3)
Here this article related to :-
- ibps notes