Syllogism / Statements & Conclusions for the Assam Police Constable (AB & UB) Exam
Syllogism, also called Statements and Conclusions, is a reasoning topic of the SLPRB Assam Police Constable (AB & UB) examination in which two or more statements are given and the candidate must decide which conclusions follow from them. The statements must be accepted as true even if they look unusual, and the conclusions must be tested by logic alone. The topic needs no calculation and no facts, only correct reasoning with the help of simple circle diagrams. With a little practice it becomes one of the surest and quickest topics. This page explains the statement forms, the rules of conversion, the diagram method and the traps that cost marks. The material follows the standard reasoning reference books used for Assam recruitment examinations and is reviewed before it is published.
Meaning and Form
A syllogism has two parts, the statements and the conclusions. The statements are the facts that are given, and the conclusions are the sentences that may or may not follow from them. The four standard forms of a statement are All A are B, Some A are B, No A is B, and Some A are not B. The task is to check whether a conclusion is definitely true on the basis of the statements. A conclusion that is merely possible, but not certain, does not follow.
Valid Conversions
- All A are B gives Some B are A.
- Some A are B gives Some B are A.
- No A is B gives No B is A.
- Some A are not B does not convert.
- All A are B does not give All B are A.
The Two Rules That Give No Conclusion
Two particular statements, that is two statements of the Some type, give no definite conclusion. Two negative statements, that is two statements of the No or the Some-not type, also give no definite conclusion. These two rules remove many wrong conclusions at once and should be remembered first.
The Circle Diagram Method
The safest way to solve a syllogism is to draw circles. For All A are B, draw the circle of A inside the circle of B. For No A is B, draw the two circles apart without any overlap. For Some A are B, draw the circles overlapping so that a part is common. Then test each conclusion against every possible arrangement of the circles. A conclusion follows only when it is true in every arrangement; if it fails in even one arrangement, it does not follow.
Possibility Conclusions
Some questions use the word possibility, as in whether it is possible that all A are B. Here the candidate does not look for certainty but asks whether the conclusion can be made true without contradicting the statements. If it can, the possibility conclusion follows. This type is answered with the same circles, only the question is different, and it should be practised separately.
Worked Examples
Example one: statements All pens are books and All books are bags. The pen circle is inside the book circle and the book circle is inside the bag circle, so the conclusion All pens are bags definitely follows, and so does Some bags are pens. Example two: statements Some pens are books and Some books are bags. Here the pen and bag circles need not touch at all, so the conclusion Some pens are bags does not follow. Example three: statements No cat is a dog and All dogs are animals. The dogs, which are animals, are certainly not cats, so the conclusion Some animals are not cats follows.
How This Topic Appears in the Examination
The topic usually appears as two to four objective questions of one mark each, often as a set of two statements followed by two or three conclusions. The candidate must mark which of the conclusions follow. Because the same statements are used for several conclusions, drawing the diagram once saves time and prevents confusion.
Shortcuts and Speed Methods
- Always draw the circles instead of reasoning in words.
- Remember the two easy conversions, All A are B gives Some B are A, and Some A are B gives Some B are A.
- Reject a conclusion that fails in even one arrangement.
- For possibility conclusions, check whether the conclusion can be made true without contradicting the statements.
- Use short names for the classes and attempt the definite conclusions before the possibility ones.
Common Mistakes to Avoid
- Using real-world knowledge instead of the given statements.
- Accepting a conclusion that is only possible, not certain.
- Forgetting the valid conversions.
- Drawing only one arrangement and not testing the others.
- Trying to solve without a diagram and losing track of the classes.
Preparation Plan
- Learn the four statement forms and their conversions.
- Practise drawing circles for every question.
- Solve possibility questions separately.
- Check each conclusion against every possible diagram.
- Practise daily until the rules become automatic.
More Practice Questions
- From All roses are flowers and Some flowers fade quickly, the conclusion Some roses fade quickly does not follow, but Some flowers are roses does follow.
- From All students are honest and All honest are poor, the conclusion All students are poor follows.
- From Some doctors are rich and All rich are happy, the conclusion Some doctors are happy follows.
- From No man is immortal and All kings are men, the conclusion No king is immortal follows.
- From Some books are pens and No pen is a pencil, the conclusion Some books are not pencils follows.
Quick Revision Checklist
- Four statement forms: All, Some, No, Some-not.
- Conversions of the All and Some statements.
- Two particular statements give no conclusion.
- Two negative statements give no conclusion.
- A conclusion follows only if it is true in every diagram.
Frequently Asked Questions
What is syllogism?
Syllogism is a reasoning topic in which statements are given and the candidate must decide which conclusions follow from them, treating every statement as true.
Should I use real-world knowledge in syllogism?
No. The statements must be accepted as true and the conclusions tested by logic alone, even if a statement seems unusual in real life.
What is the easiest method to solve syllogism?
The circle diagram method. Draw circles for the classes and check whether the conclusion is true in every possible arrangement.
When does a conclusion definitely follow?
A conclusion follows only when it is true in every possible arrangement. If it fails in even one arrangement, it does not follow.
What does All A are B imply?
It means every A is a B and allows the valid conversion Some B are A. It does not mean that all B are A.