What should come in place of the question mark $(?)$ in the following equation?
$39.97 \%$ of $649.8 \div 13.05 = 45.12 - ?$

What approximate value will come in place of the question mark $(?)$ in the given equation? (You are not expected to calculate the exact value)
$\frac{7702}{43.96} + 25.11 \times 45.88 = ? \times 15$

If $\frac{144}{0.144} = \frac{14.4}{x}$,then the value of $x$ is

What will be the remainder when $252^{126} + 244^{152}$ is divided by $10$?

Between two fractions $\frac{1}{2}$ and $\frac{1}{8},$ how many fractions are there in all?

$\frac{1}{8}$ of $\frac{2}{3}$ of $\frac{3}{5}$ of $1715 = ?$