$\frac{5 \times 1.6 - 2 \times 1.4}{1.3} = ?$

If $a, b, c$ are three non-zero real numbers such that $a+b+c=0$ and $b^{2} \neq ca,$ then the value of $\frac{a^{2}+b^{2}+c^{2}}{b^{2}-ca}$ is

$A$ man has some hens and cows. If the number of heads is $48$ and the number of legs is $140$,then the number of hens is:

The value of $\frac{1}{1 \times 2} + \frac{1}{2 \times 3} + \frac{1}{3 \times 4} + \ldots + \frac{1}{9 \times 10}$ is

What will come in the place of the question mark $(?)$ in the following equation?
$2 \frac{1}{8} - 1 \frac{1}{16} = ? + 1 \frac{1}{32} - 1 \frac{9}{64}$

If $x = \sqrt{3} + \frac{1}{\sqrt{3}}$,then the value of $\left(x - \frac{\sqrt{126}}{\sqrt{42}}\right) + \left(x - \frac{1}{x - \frac{2\sqrt{3}}{3}}\right)$ is