Question

Let $A=\{p,q,r,4,5\}$ and $B=\{p,q,r\},$ then

• A. $n\left(A\right)=n\left(B\right)$
• B. $A=B$
• C. $A\ne B$
• D. None of these.

Answer 1

The correct option is C $A\ne B$

Given $A=\{p,q,r,4,5\}\Rightarrow n\left(A\right)=5$
$B=\{p,q,r\}\Rightarrow n\left(B\right)=3$
Since, $n\left(A\right)\ne n\left(B\right)$ therefore
$A\ne B$