Write the following as intervals :

$\{ x:x \in R, – 12\, < \,x\, < \, – 10\} $

Decide, among the following sets, which sets are subsets of one and another:

$A = \{ x:x \in R$ and $x$ satisfy ${x^2} – 8x + 12 = 0 \} ,$

$B=\{2,4,6\}, C=\{2,4,6,8 \ldots\}, D=\{6\}$

Which of the following sets are finite or infinite.

The set of prime numbers less than $99$

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

$\{1,2,3\}\subset A$

Write the following sets in roster form :

$B = \{ x:x$ is a natural number less than ${\rm{ }}6\} $