If $X$ and $Y$ are two sets and $X^{\prime}$ denotes the complement of $X$, then $X \cap(X \cup Y)^{\prime}$ is equal to
The set $\{x \in R: 1 \leq x<2\}$ can be written as ............. .
The set $\{x \in R: 1 \leq x<2\}$ can be written as $(1,2)$.
When $A=\phi$, then number of elements in $P(A)$ is .............. .
$$\begin{aligned} \therefore \quad & A =\phi \quad \Rightarrow n(A)=0 \\ & n\{P(A)\} =2^{n(A)}=2^0=1 \end{aligned} $$ So, number of element in $P(A)$ is 1 .
If $A$ and $B$ are finite sets, such that $A \subset B$, then $n(A \cup B)$ is equal to ............ .
If $A$ and $B$ are two finite sets such that $A \subset B$, then $n(A \cup B)=n(B)$.
If $A$ and $B$ are any two sets, then $A-B$ is equal to ............. .
If $A$ and $B$ are any two sets, then $A-B=A \cap B^{\prime}$
$\therefore \quad A-B=A \cap B^{\prime}$