2.1.5i:

(I'll write tex code when symbols aren't available in html.) The set on the right has only one element in it. That is, it is equal to {x}, where x={\emptset, {\emptyset}}. Neither of the elements of the set on the left, \emptyset or {\emptyset}, is equal to x. So the statement is false.

In fact these two sets are disjoint, meaning their intersection is \emptyset, which is a

strongerstatement than (A is not a subset of B).