$74.01 \%$ of $1301 + 9.99 \%$ of $1901 = ?$

$5.6 \times 12.5 \div 0.5 + 15.5 = ? + 49.5$

The square root of $\left[\frac{(3.25)^{3}}{3.25-1}-\left(3.25+(3.25)^{2}+1\right)\right]$ is equal to

$(\sqrt{9})^{3} \times (\sqrt{81})^{5} \div 27^{2} = 3^{?}$

$A$ number $N$ is a positive three-digit number. If $x$ is in its hundred's place and $y$ is in its unit's place,then the number $N - 100x - y$ is always divisible by

What is the least number that must be added to $4042$ to make it a perfect square?