Let $A=\{1,2,3,4,5,6\} .$ Insert the appropriate symbol $\in$ or $\notin$ in the blank spaces:
$10 \, .........\, A $
State whether each of the following set is finite or infinite :
The set of lines which are parallel to the $x\,-$ axis
Examine whether the following statements are true or false :
$\{ a\} \in \{ a,b,c\} $
Write the following sets in roster form :
$\mathrm{E} =$ The set of all letters in the world $\mathrm{TRIGONOMETRY}$
Which of the following are sets ? Justify your answer.
The collection of all natural numbers less than $100 .$