CAT 2019 Shift 1 Paper

Let the total score of the exam be $100\mathit{x}$
Meena's before review $=40\%$ of $100\mathit{x}=40\mathit{x}$.
Her score after review $=40\mathit{x}+50\%$ of $40\mathit{x}=60\mathit{x}$.
Passing marks $=60\mathit{x}+35..\left(1\right)$
Her score after increasing it by $20\%$ of post revie score $=60\mathit{x}+20\%$ of $60\mathit{x}=72\mathit{x}$
Passing marks $=72\mathit{x}-7....$ (2)
Equating (1) and (2)
$72\mathit{x}-7=60\mathit{x}+35$
$\Rightarrow \mathit{x}=3.5$
Hence, Total Marks $=100\mathit{x}=350$ and passing marks $=60\mathit{x}+35=245$
Therefore, passing percentage $=\frac{245}{350}\times 100=70\%$