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

What fraction must be subtracted from the sum of $\frac{1}{4}$ and $\frac{1}{6}$ to have an average of $\frac{1}{12}$ of all the three fractions?

The value of $(3+2 \sqrt{2})^{-3}+(3-2 \sqrt{2})^{-3}$ is

If $x + (1/x) = 2$,then what is the value of $x^{21} + (1/x^{1331})$?

$\frac{1}{\left(2 \frac{1}{3}\right)}+\frac{1}{\left(1 \frac{3}{4}\right)}$ is equal to

What approximate value will come in place of the question mark $(?)$ in the given equation? (You are not expected to calculate the exact value)
$24.98^{2} \times \frac{16.02^{2}}{(7.98 \times 15.04)} \times 38.93 = 130 \times ?^{2}$