UGCPQ Q.18
- Option : A
- Explanation : A proposition is a subaltern of another if it
must be true in case its superaltern is true,
and its superaltern must be false in case the
subaltern is false.
Sub-contrary propositions are those two propositions which can both be true but cannot both be false.
Two propositions are contrary, if they cannot both be true, but they might both be false. They have same subjects and predicates; and, are different in qualities but have the same universal quantities.
Two propositions are contradictory, if one of them is a denial of another. They cannot both be true, and cannot both be false. They have same subjects and predicates but are different in quantities (all, some, no) as well as qualities.
