Syllogism has appeared only in ASO 2012 (two questions), but OSSC and other Odisha exams ask it often. The safe method is to draw every possible Venn diagram for the statements and accept a conclusion only if it is true in all of them.
The four statement types
| Statement | Diagram | Gives for certain |
|---|---|---|
| All A are B | A circle inside B | Some A are B, Some B are A |
| Some A are B | A and B overlap | Some B are A |
| No A are B | A and B separate | No B is A, Some A are not B |
| Some A are not B | Part of A lies outside B | Nothing reversible |
Two-statement rules
- All + All → All (All A are B, All B are C → All A are C).
- All + No → No. Some + All → Some. Some + No → Some … not.
- Some + Some → no definite conclusion.
- No + No → no definite conclusion.
ASO 2012 pattern
Three segments are given, and you check whether the third follows from the first two. Some boys are tall + all tall persons are smart → some boys are smart ✓.