In the following state whether $\mathrm{A = B}$ or not :

$A = \{ 2,4,6,8,10\} ;B = \{ x:x$ is positiveeven integer and $x\, \le \,10\} $

State which of the following sets are finite or infinite :

$\{ x:x \in N$ and ${x^2} = 4\} $

Write the following sets in the set-builder form :

$\{ 2,4,6 \ldots \} $

Let $A=\{a, e, i, o, u\}$ and $B=\{a, i, u\} .$ Show that $A \cup B=A$

The number of proper subsets of the set $\{1, 2, 3\}$ is

Let $S=\{1,2,3, \ldots, 40)$ and let $A$ be a subset of $S$ such that no two elements in $A$ have their sum divisible by 5 . What is the maximum number of elements possible in $A$ ?