Given the sets $A = \{ 1,\,2,\,3\} ,\,B = \{ 3,4\} , C = \{4, 5, 6\}$, then $A \cup (B \cap C)$ is

If $aN = \{ ax:x \in N\} ,$ then the set $3N \cap 7N$ is .....$N$

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

Let $A$ and $B$ be two sets such that $n(A) = 0.16,\,n(B) = 0.14,\,n(A \cup B) = 0.25$. Then $n(A \cap B)$ is equal to

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?

Let $A, B$ and $C$ be sets such that $\phi  \ne A \cap B \subseteq C$. Then which of the following statements is not true ?