In a class of $80$ students,each student got sweets that are $15 \%$ of the total number of students. How many sweets were there?

An army lost $10 \%$ of its men in war,$10 \%$ of the remaining died due to disease,and $10 \%$ of the rest were declared disabled. Thus,the strength of the army was reduced to $7,29,000$ active men. What was the original strength of the army?

Rajeev buys goods worth Rs. $6650$. He gets a rebate of $6\%$ on it. After getting the rebate,he pays sales tax at the rate of $10\%$. Find the total amount he will have to pay for the goods.

If the length of a rectangle is increased by $20\%$ and its breadth is decreased by $10\%$,what will be the impact on its area?

What per cent of $\frac{2}{7}$ is $\frac{1}{35} ?$

From the salary of an officer,$10 \%$ is deducted as house rent,$20 \%$ of the rest,he spends on conveyance,$20 \%$ of the rest he pays as income tax and $10 \%$ of the balance,he spends on clothes. If he is left with ₹ $15552$,find his total salary.