Let $A=\{1,2,3,4,5,6\} .$ Insert the appropriate symbol $\in$ or $\notin$ in the blank spaces:

$ 0\, ........\, A $

$A = \{ x:x \ne x\} $ represents

Let $A=\{1,2,\{3,4\}, 5\} .$ Which of the following statements are incorrect and why ?

$\{1,2,5\}\subset A$

Write the following as intervals :

$\{ x:x \in R,0\, \le \,x\, < \,7\} $

List all the elements of the following sers :

$B = \{ x:x$ is an integer $; - \frac{1}{2} < n < \frac{9}{2}\} $

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

$A = \{ x:x$ is a multiple of $10\} ;B = \{ 10,15,20,25,30 \ldots  \ldots \} $