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

$ 2 \, ……. \, A $

Make correct statements by filling in the symbols $\subset$ or $ \not\subset $ in the blank spaces:

$\{ x:x$ is an equilateral triangle in a plane $\}  \ldots \{ x:x$ is a triangle in the same plane $\} $

Which of the following are sets ? Justify your answer.

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

Write the following sets in the set-builder form :

$\{ 1,4,9 \ldots 100\} $

State which of the following sets are finite or infinite :

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