Are two empty sets SetA and SetB equal?

Empty set is

Define empty set .

If A and B are two non-empty sets and A - B is a null set, then "____" .

For any two non-empty sets A and B , A xx B is called as ……………….

If A and B are two non empty sets then AUB=A nn B iff

If A,B and C are three non=empty sets such that A and B are disjoint and the number of elements contained in A is equal to those contained in the set of elements common to the set A and C, then (AcupBcupC) is necessarily equal to

If A,B and C are three non=empty sets such that A and B are disjoint and the number of elements contained in A is equal to those contained in the set of elements common to the set A and C, then n(AcupBcupC) is necessarily equal to