NIFT UG 2020 Question Paper with solutions

Let the price of antique $=\mathit{₹}100$
Now, after $20\%$ of reduction
Price of antique Again, after $10\%$ of reduction.
Price of antique $=80-\frac{80\times 10}{100}=80-8=\mathit{₹}72$
Hence, total reduction of the price $=\frac{100-72}{100}\times 100\%=28\%$
Alternate Method
Here, $\mathit{x}=20\%$ and $\mathit{y}=10\%$
$\therefore$ Total required reduction $=\left(\mathit{x}+\mathit{y}-\frac{\mathit{x}\mathit{y}}{100}\right)\%$
$=\left(20+10-\frac{20\times 10}{100}\right)\%$
$=\left(30-2\right)\%=28\%$