If $A, B$ and $C$ are any three sets, then $A - (B \cap C)$ is equal to

Consider the following relations :

$(1) \,\,\,A - B = A - (A \cap B)$

$(2) \,\,\,A = (A \cap B) \cup (A - B)$

$(3) \,\,\,A - (B \cup C) = (A - B) \cup (A - C)$

which of these is/are correct

If $X$ and $Y$ are two sets such that $X \cup Y$ has $50$ elements, $X$ has $28$ elements and $Y$ has $32$ elements, how many elements does $X$ $\cap$ $Y$ have?

Show that the following four conditions are equivalent:

$(i)A \subset B\,\,\,({\rm{ ii }})A - B = \phi \quad (iii)A \cup B = B\quad (iv)A \cap B = A$

If $X$ and $Y$ are two sets such that $X$ has $40$ elements, $X \cup Y$ has $60$ elements and $X$ $\cap\, Y$ has $10$ elements, how many elements does $Y$ have?

If $A = \{x : x$ is a multiple of $4\}$ and $B = \{x : x$ is a multiple of $6\}$ then $A \cap B$ consists of all multiples of