Ramu used to spend 72% of his income. His income is increased by 12% and he increases his expenditure by 5%. If Ramu earlier saved Rs.y and after the increases he now saves Rs.x then what is the value of $$\frac{(x-y)}y×100 \%$$​?

Correct option is D

Given : 

Initial expenditure  = 72%

Income increase = 12%

Expenditure increase = 5%

 Formula used: 

$$Saving = Income - Expenditure$$

​​​$$\text{Percentage change in saving} = \frac{ \text{New Saving - Initial Saving}} {\text{ Initial Saving}} × 100$$​​

Solution :

Let Initial income  = 100

Initial Expenditure = 72% of 100 = 72

Initial Savings (y) = 100 - 72 = 28

Income = 100 $$\times$$ 1.12 = 112

New Expenditure = 72 $$\times$$ (1 +  $$\frac{5}{100}$$​)

New Expenditure = 72 $$\times$$ 1.05 = 75.6 

Percentage change in savings:

= $$\frac{36.4-28}{28}$$​ $$\times$$ 100

=  (  $$\frac{8.4}{28}$$​) $$\times$$100 

= 0.3  $$\times$$100

= 30%  

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