SSC CGL Model Paper 9

Increase in price- 30% =$\frac{3}{10}$
If initial price Rs 10x/kg
Final price is Rs 13x/kg
Increase in expenditure-10% $=\frac{1}{10}$
If initial expenditure is Rs. 10 y
Then, increased expenditure is Rs 11y
Now,
Consumption = $\frac{\mathrm{expenditure}}{\mathrm{Price}}$
So, initial consumption = $\frac{10\mathit{y}}{10\mathit{x}}=\frac{\mathit{y}}{\mathit{x}}$
Final consum ption = $\frac{11\mathit{y}}{13\mathit{x}}$
Required % $=\frac{\frac{\mathit{y}}{\mathit{x}}-\frac{11\mathit{y}}{13\mathit{x}}}{\frac{\mathit{y}}{\mathit{x}}}\times 100\%$
$=\frac{2}{13}\times 100\%=15\frac{5}{13}\%$