The correct expression of $5 . \overline{45}$ in the fractional form is

$7 \frac{11}{18} + 13 \frac{1}{9} + 5 \frac{7}{9} - 16 \frac{2}{3} = ?$

Evaluate $\frac{0.53 \times 0.53 - 2 \times 0.53 \times 0.41 + 0.41 \times 0.41}{0.53 - 0.41}$

What will come in the place of the question mark $(?)$ in the following expression?
$\frac{28}{65} \times \frac{195}{308} \div \frac{39}{44} + \frac{5}{26} = ?$

Twenty-one times a positive number is less than its square by $100$. The value of the positive number is:

What approximate value will come in place of the question mark $(?)$ in the given equation? (You are not expected to calculate the exact value)
$\frac{1810}{24.05} \times 7.95 + 11.02 \times 18.88 = ? - 306$