Write the following sets in roster form :
$C = \{ x:x{\rm{ }}$ is a two-digit natural number such that sum of its digits is $8\} $
$C = \{ x:x{\rm{ }}$ is a two-digit natural number such that the sumof its digits is $8\} $
The elements of this set are $17,26,35,44,53,62,71$ and $80$ only.
Therefore, this set can be written in roster form as $C=\{17,26,35,44,53,62,71,80\}$
Which of the following are examples of the null set
$\{ x:x$ is a natural numbers, $x\, < \,5$ and $x\, > \,7\} $
Which set is the subset of all given sets
Let $A, B$ and $C$ be three sets. If $A \in B$ and $B \subset C$, is it true that $A$ $\subset$ $C$ ?. If not, give an example.
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 sets are finite or infinite.
$\{1,2,3 \ldots .\}$