Answer to Question #45753 in Math for sapna

Question

In the context of admission to IGOU, give examples of the following:
i) an implication;
ii) the converse of (i) above;
iii) a two-way implication which is true;
iv) a statement involving both ∀and ∃.
v) the contrapositive of (i) above. (10)
b) Prove that if A and B are any two sets such that A ⊆B, then A ∪B = B
i) by direct method;
ii) by proving its contrapositive;
iii) by contradiction. (10)