State which of the following sets are finite or infinite :

$\{ x:x \in N$ and $x$ is prime $\} $

Which of the following are sets ? Justify your answer.

The collection of all even integers.

Which of the following are examples of the null set

$\{ x:x$ is a natural numbers, $x\, < \,5$ and $x\, > \,7\} $

Which of the following are examples of the null set

Set of odd natural numbers divisible by $2$

Which of the following sets are finite or infinite.

$\{1,2,3, \ldots 99,100\}$

List all the elements of the following sers :

$E = \{ x:x$ is a month of a year not having $ 31 $ days ${\rm{ }}\} $