How to solve the problem on income and expenditure? [closed]

Question :

"The annual earning of Mr. Sikkawala is Rs.$4$ lakhs per annum for the first year of his job and his expenditure was $50$%. Later on for the next $3$ years his average income increases by Rs $40000$ per annum and the saving was $40$%, $30$%, $20$%$ of the income. What is the percentage of his total savings over the total expenditure if there is no any interest is applied on the savings for these four years."

Doubt:

I want to have a paradigm thought process behind the problem. Some assistance about the same will be most welcome.

I don't know what "paradigm" you are after, but the information given can be summarized in a table:

$$\begin{array}{c|ccc} \text{Year}&\text{Income}&\text{% Savings}&\text{% Expenditures}\\\hline 1&400000&50\%&50\%\\ 2&440000&40\%&60\%\\ 3&480000&30\%&70\%\\ 4&520000&20\%&80\%\end{array}$$

From this you can calculate the actual amount of money saved each year, and spent each year. Sum those up to get total savings and the total expenditures.

I am not entirely sure how to interpret the phrase "percentage of this total savings over the total expenditure". It sounds like they want you to divide the savings by the expenditures and convert that ratio to a percentage. But that is a rather odd and somewhat meaningless value to calculate, so maybe I am misinterpreting the instruction.