Write down all the subsets of the following sets
$\{ 1,2,3\} $
Which of the following are sets ? Justify your answer.
The collection of all the months of a year beginning with the letter $\mathrm{J}.$
Which of the following sets are finite or infinite.
The set of months of a year
Let $A=\{1,2,\{3,4\}, 5\} .$ Which of the following statements are incorrect and why ?
$\varnothing \in A$
Write the following as intervals :
$\{ x:x \in R, - 12\, < \,x\, < \, - 10\} $