Question

Sonali invests 15% of her monthly salary in insurance policies. She spends 55% of her monthly salary in shopping and on household expenses. She saves the remaining amount of Rs. 12,750. What is Sonali's monthly income?

• A. Rs. 42,500
• B. Rs. 38,800
• C. Rs. 40,000
• D. Rs. 35,500

Hint:

Find what percentage of the salary is left as savings, then use the given rupee saving to find the value of 1% of salary.

Answer 1

The Correct Option is A

We can also solve this without introducing a variable, by working with the saved percentage directly.

1. Since insurance takes 15% and shopping and household expenses take 55%, together they use up $15\%+55\%=70\%$ of the salary.
2. What remains as savings is $100\%-70\%=30\%$ of the monthly salary.
3. This 30% equals Rs. 12,750, so 1% of the salary is $12750 \div 30 = 425$.
4. The full salary, that is 100%, is $425 \times 100 = 42{,}500$.

Working in percentages directly skips writing an algebraic equation and gets to the same place.

Let's summarize:

• Sonali's monthly income is Rs. 42,500, which is option A.

Whenever a problem gives one part as a percentage and its rupee value, finding the value of 1% first is usually the fastest path.