Which of the following is a true statement

- A
$\{a\} \subseteq \{a, b, c\}$

- B
$\{a\} \in \{a, b, c\}$

- C
$\phi \in \{a, b, c\}$

- D
None of these

The number of elements in the set $\{x \in R :(|x|-3)|x+4|=6\}$ is equal to

- [JEE MAIN 2021]

State which of the following sets are finite or infinite :

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

Write the following as intervals :

$\{ x:x \in R, - 4\, < \,x\, \le \,6\} $

Which of the following are sets ? Justify your answer.

A collection of novels written by the writer Munshi Prem Chand.

Which of the following are sets ? Justify your answer.

The collection of all the months of a year beginning with the letter $\mathrm{J}.$