What will come in the place of the question mark $(?)$ in the following expression?
$3 \frac{3}{4} + 4 \frac{2}{5} - 3 \frac{1}{8} = ?$

What will come in place of the question mark (?) in the following equation?
$4003 \times 77 - 21015 = ? \times 116$

The value of $\frac{3}{1^{2} \cdot 2^{2}}+\frac{5}{2^{2} \cdot 3^{2}}+\frac{7}{3^{2} \cdot 4^{2}}+\frac{9}{4^{2} \cdot 5^{2}}+\frac{11}{5^{2} \cdot 6^{2}}+\frac{13}{6^{2} \cdot 7^{2}}+\frac{15}{7^{2} \cdot 8^{2}}+\frac{17}{8^{2} \cdot 9^{2}}+\frac{19}{9^{2} \cdot 10^{2}}$ is

$6 \frac{1}{7} + 15 \frac{2}{3} + 11 \frac{1}{6} = 33 \frac{1}{21} - ?$

What will come in the place of the question mark $(?)$ in the following expression?
$\frac{343 \times 49}{216 \times 16 \times 81} = ?$

$\frac{\sqrt{7}}{\sqrt{16+6 \sqrt{7}}-\sqrt{16-6 \sqrt{7}}}$ is equal to