NIMCET 2020 Question Paper with solutions

Let A be the set of students who read "Hitavad" and B the set of students who read "Hindustan".
From the given information:
$\mathit{n}\left(\mathit{A}\cup \mathit{B}\right)=50-10=40$.
$\mathit{n}\left(\mathit{A}\right)=30$
$\mathit{n}\left(\mathit{B}\right)=35$.
By using $\mathit{n}\left(\mathit{A}\cup \mathit{B}\right)=\mathit{n}\left(\mathit{A}\right)+\mathit{n}\left(\mathit{B}\right)-\mathit{n}\left(\mathit{A}\cap \mathit{B}\right)$, we get:
$40=30+35-\mathit{n}\left(\mathit{A}\cap \mathit{B}\right)$
$\Rightarrow \mathit{n}\left(\mathit{A}\cap \mathit{B}\right)=25$
$\therefore$ The number of students who read both "Hitavad" and "Hindustan" newpapers is $\mathit{n}\left(\mathit{A}\cap \mathit{B}\right)=25$.