Question

Kailash used to spend 85% of his income. When his income increased by 36% his expenses also increased by 40% of his earlier expenses. How much percentage of his earning he saves now ?

Answer 1

Let the income be Rs 100.
Expenditure = 85% of Rs 100 = $\frac{85}{100}\times 100=\mathrm{Rs}85$
New salary is 36% more than previous salary
So, new salary = 100 + $\frac{36}{100}\times 100$ = Rs 136
New expenditure increased by 40% of earlier expense.
New expenditure = $\left(100+\frac{40}{100}\times 100\right)\times 85=\mathrm{Rs}119$
Amount he saves now = New salary $-$ new expenditure
= Rs 136 $-$ Rs 119 = Rs 17
% saving = $\frac{17}{136}\times 100=12.5\%$