In the following,state whether $A = B$ or not:
$A = \{ x: x \text{ is a multiple of } 10 \}$
$B = \{ 10, 15, 20, 25, 30, \ldots \}$

Given the sets $A = \{1, 3, 5\}$,$B = \{2, 4, 6\}$ and $C = \{0, 2, 4, 6, 8\}$,which of the following may be considered as a universal set for all the three sets $A$,$B$ and $C$?
$X = \{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10\}$

If $P, Q$ and $R$ are subsets of $A$,then $R \times (P \cup Q) = $

Let $A$ and $B$ be sets. If $A \cap X = B \cap X = \phi$ and $A \cup X = B \cup X$ for some set $X$,show that $A = B$. (Hint: Use $A = A \cap (A \cup X)$,$B = B \cap (B \cup X)$ and the Distributive law.)

Write down all the subsets of the following set: $\emptyset $

If $A$ and $B$ are two sets,then $A \cup (A \cap B)$ is equal to