What least number must be added to $7231$ so that the resulting number is exactly divisible by $5$ and $9$ together?

$A$ number consists of two digits such that the digit in the ten's place is less by $2$ than the digit in the unit's place. Three times the number added to $\frac{6}{7}$ times the number obtained by reversing the digits equals $108$. The sum of the digits in the number is:

If $2 \frac{1}{2}$ is added to a number and the sum is multiplied by $4 \frac{1}{2}$,and $3$ is added to the product,and then dividing the sum by $1 \frac{1}{5}$,the quotient becomes $25$. What is the number?

$8000 \div 16 - 200 = ? \times 6$

$149.9 \%$ of $149.9 + 149.9 = ?$

Find the square root of $(2.25)^{2} + 16 - 4(2.25) - \frac{(2.25)^{3}}{2.25 + 4} ?$