Class 9 · Chapter 9
Propositions and their Converses
What is a statement, when is it true, and how does a converse behave differently?
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Ganita Manjari · Class 9 (2026-27)
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Detailed theory
" is prime" is a proposition (true). " is even" is not — it depends on . Sentences that are opinions or questions are not propositions.
Key concepts & formulas
01
A **proposition** is a sentence that is definitely true or definitely false — never both.
02
Logical connectives: **AND** (), **OR** (), **NOT** (), **IF-THEN** ().
03
Conditional : read as "if , then ".
04
**Converse** of is — a different statement whose truth is independent.
05
Contrapositive has the same truth value as the original.