If $A = \{ 1,\,2,\,3,\,4,\,5\} ,$ then the number of proper subsets of $A$ is

Write the following as intervals :

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

Which of the following sets are finite or infinite.

The set of positive integers greater than $100$

State which of the following sets are finite or infinite :

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

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

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

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

$\varnothing \subset A$