$A$ salesman is allowed $5 \frac{1}{2} \%$ discount on the total sales made by him plus a bonus of $\frac{1}{2} \%$ on the sales made over $₹ 10000$. If his total earnings are $₹ 1990$,find the total sales.

If the price of a shirt is increased by $25 \%$ and then decreased by $30 \%$,then what will be the net effect?

In my office,at least $50 \%$ of the people read an e-newspaper. Among those who read an e-newspaper,at most $25 \%$ read more than one e-paper. Only one of the following statements follows from the statements given below. Which one is it?

$45 \%$ of $1500 + 35 \%$ of $1700 = ? \%$ of $3175$

Amit donated $20\%$ of his income to a school and deposited $20\%$ of the remainder in his bank. If he has $₹ 12800$ now,what is the income (in $₹$) of Amit?

The population of a town increases by $2.5 \%$ annually but decreases by $0.5 \%$ every year due to migration. What will be the net percentage increase in population after $2$ years (in $\%$)?