$3.5$ can be expressed in terms of percentage as:

If $50 \%$ of $(x-y) = 30 \%$ of $(x+y)$,then what percent of $x$ is $y$?

Mrs. Jain invests $14 \%$ of her monthly salary,i.e.,$Rs. 7014$ in Insurance Policies. Later she invests $21 \%$ of her monthly salary on Family Mediclaim Policies; also she invests another $6.5 \%$ of her salary on Mutual Funds. What is the total annual amount invested by Mrs. Jain?

$A, B$ and $C$ start a business by investing $Rs. 70000$ that earns them a profit of $Rs. 42000$ at the end of the year. $A$ invests his share in the profit in a scheme that gives $10\%$ interest compounded annually and $B$ invests his share in a scheme that gives $20\%$ interest compounded annually. $A$ gets $Rs. 2520$ as interest at the end of $2$ years and $B$ gets an interest of $Rs. 4200$ at the end of one year. Find $C$'s investment in the business.

$A$ man donates $30\%$ of his wealth to charity. He gives $30\%$ and $25\%$ of the remaining wealth to his wife and son respectively. The rest he divides equally between his three daughters. One of his daughters gets $Rs$ $42$ lakh as her share. What was the man's total wealth (in $Rs$ lakhs)?

In a certain quantity of ghee, $60 \%$ is pure ghee and $40 \%$ is vanaspati. If $10 \text{ kg}$ of pure ghee is added, the concentration of vanaspati ghee becomes $20 \%$. What was the original quantity (in $\text{ kg}$)?