Solution:
(i) It is known to us that a conditional statement is logically equivalent to its contrapositive.
Contrapositive: If $x\ne 3$, then $x\ne y$ or $y\ne3$
(ii) It is known to us that a conditional statement is logically equivalent to its contrapositive.
Contrapositive: If $n$ is not an integer, then it isn’t a natural no.