Sunil decided to donate $5 \%$ of his salary. On the day of donation,he changed his mind and donated $₹ 1687.50$,which was $75 \%$ of what he had decided earlier. How much is Sunil's salary?

An ore contains $23 \%$ copper. To get $69 \text{ kg}$ of copper, the quantity of the ore required is: (in $\text{ kg}$)

The production of a company has ups and downs every year. The production increases for two consecutive years consistently by $15 \%$ and in the third year it decreases by $10 \%$. Again in the next two years it increases by $15 \%$ each year and decreases by $10 \%$ in the third year. If we start counting from the year $1998$,approximately what will be the effect on the production of the company in $2002$?

In a class of $50$ students and $5$ teachers,each student received sweets equal to $12 \%$ of the total number of students,and each teacher received sweets equal to $20 \%$ of the total number of students. How many sweets were there in total?

Samar spends $52 \%$ of his monthly salary on household expenditure and $23 \%$ on miscellaneous expenditure. If he is left with $Rs. 4500$,what is his monthly salary?

$A$ person who spends $66 \frac{2}{3} \%$ of his income is able to save $₹ 1200$ per month. His monthly expenses (in $₹$) are