Two numbers $A$ and $B$ are such that the sum of $5 \%$ of $A$ and $4 \%$ of $B$ is $\frac{2}{3}$ of the sum of $6 \%$ of $A$ and $8 \%$ of $B$. The ratio $A:B$ is

$A$ shopkeeper marks the prices of his goods at $25 \%$ higher than the original price. After that,he allows a discount of $12 \%$. What profit or loss did he make?

If $18 \%$ of a number is $720,$ then what is $81 \%$ of the same number?

There are $1400$ students in the school. $25 \%$ of them wear spectacles and $\frac{2}{7}$ of those who wear spectacles are boys. How many girls in the school wear spectacles?

If in an examination $20 \%$ students failed in Hindi,$25 \%$ failed in English,and $7 \%$ failed in both subjects,then what is the percentage of students who failed in at least one of the subjects (in $\%$)?

$A$ man spends $75 \%$ of his income. His income increases by $20 \%$ and his expenditure also increases by $10 \%$. The percentage of increase in his savings is (in $\%$)