$405$ sweets were distributed equally among children in such a way that the number of sweets received by each child is $20 \%$ of the total number of children. How many sweets did each child receive?

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.

$A$ number is increased by $20 \%$ and then decreased by $20 \%$. What is the final percentage change in the number?

What percentage of numbers from $1$ to $70$ have squares that end in the digit $1$?

If the numerator of a fraction is increased by $150 \%$ and the denominator of the fraction is increased by $300 \%$,the resultant fraction is $\frac{5}{18}$. What is the original fraction?

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?