If $A, B$ and $C$ are three sets such that $A \cap B = A \cap C$ and $A \cup B = A \cup C$ then
$A = C$
$B = C$
$\;A \cap B = \emptyset $
$\;A = B$
Sets $A$ and $B$ have $3$ and $6$ elements respectively. What can be the minimum number of elements in $A \cup B$
If $A$ and $B$ are two sets such that $A \subset B$, then what is $A \cup B ?$
If $A=\{3,6,9,12,15,18,21\}, B=\{4,8,12,16,20\},$ $C=\{2,4,6,8,10,12,14,16\}, D=\{5,10,15,20\} ;$ find
$C-D$
Let $A = \{a, b, c\}, B = \{b, c, d\}, C = \{a, b, d, e\},$ then $A \cap (B \cup C)$ is
Find the union of each of the following pairs of sets :
$A=\{1,2,3\}, B=\varnothing$