State which of the following sets are finite or infinite :
$\{ x:x \in N$ and $(x - 1)(x - 2) = 0\} $
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 $\} $
The number of non-empty subsets of the set $\{1, 2, 3, 4\}$ is
In rule method the null set is represented by