If $A, B, C$ are three sets, then $A \cap (B \cup C)$ is equal to
$(A \cup B) \cap (A - C)$
$(A \cap B) \cup (A \cap C)$
$(A \cup B) \cup (A \cup C)$
None of these
Find the union of each of the following pairs of sets :
$A=\{1,2,3\}, B=\varnothing$
Show that for any sets $\mathrm{A}$ and $\mathrm{B}$, $A=(A \cap B) \cup(A-B)$ and $A \cup(B-A)=(A \cup B).$
If ${N_a} = [an:n \in N\} ,$ then ${N_5} \cap {N_7} = $
Let $A=\{2,4,6,8\}$ and $B=\{6,8,10,12\} .$ Find $A \cup B$
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?