Anu spends 68% of her monthly income. If her monthly income increases by 20% and her monthly savings increase by $$9\frac{3}{8}\%$$, then the percentage increase in her monthly expenditure is:

Let the initial salary of Anu be 100%.

Initially Expenditure of Anu = 68%

Saving = 100 -68 = 32%

Salary after 20% increment =  100 $$\times 120/100 = 120%$$

Saving after increment = 32% $$\times \frac{100 + 9\frac{3}{8}}{100}$$ = 32% $$\times \frac{109.375}{100}$$ = 35%

Expenditure = 120 - 35 = 85%

Percentage increase in her monthly expenditure = $$\frac{85 - 68}{68} \times 100 = \frac{17}{68} \times 100$$ = 25%