A man spends 87% of his income. His income increased by 18% and he increased his expenditure by 17%. His savings will then be increased by : (Consider up to two decimals only)

Given

Initial percentage of income spent = 87%

Increase in income = 18%

Increase in expenditure = 17%

Concept:

The savings are the income minus the expenditure. A percentage change in savings can be calculated as the new savings minus the old savings divided by the old savings times 100%.

Solution:

Let income is 100

He spends 87

Saves 13

Income is increased by 18% is equal to 100 × 118% = 118

Expenditure increased  by 17% is equal to 87 × 117 = 101.79

New savings = 118 - 101.79 = 16.21

Increase in savings = 16.21 - 13 = 3.21

% increase = 3.21/13 × 100 = 24.69%

Therefore, the savings increased by 24.69%.