Sonu saves 15% of her income. If her income increases by 20% and she still saves the same amount as before, then what is the percentage increase in her expenditure? (correct to one decimal place)

23.5

Let the income of Sonu be Rs. 100x

Savings of Sonu = 100x ×\(\frac{15}{100}\)=  15x

Expenditure of Sonu = 100x – 15x =  85x

New income of Sonu = 100x × \(\frac{120}{100}\) = 120x

If savings amount same, then new expenditure = 120x – 15x = 105x

Her expenditure increased by = 105x – 85x = 20x

Her expenditure increased by =  \(\frac{20x}{85x}\) × 100 = 23.52%

= 23.5%  (approx)