List all the elements of the following sers :

$D = \{ x:x$ is a letter in the word $"\mathrm{LOYAL}" $ $\} $

Let $A=\{1,2,\{3,4\}, 5\} .$ Which of the following statements are incorrect and why ?

$\{\varnothing\} \subset A$

Examine whether the following statements are true or false :

$\{ a\}  \in \{ a,b,c\} $

Write the following sets in roster form :

$D = \{ x:x$ is a prime number which is divisor of $60\} $

Write the following intervals in set-builder form :

$\left( { - 3,0} \right)$

Consider the sets

$\phi, A=\{1,3\}, B=\{1,5,9\}, C=\{1,3,5,7,9\}$

Insert the symbol $\subset$ or $ \not\subset $ between each of the following pair of sets:

$A \ldots C$