$\left(\frac{10.3 \times 10.3 \times 10.3 + 1}{10.3 \times 10.3 - 10.3 + 1}\right)$ is equal to (in $.3$)

What value will come in place of the question mark (?) in the following question? (You are not expected to calculate the exact value)
$10^{3} \times 100^{3} + 999999999 = 10^{?} + 10^{?}$

If $\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right) \ldots\left(1-\frac{1}{70}\right)=\frac{x}{70},$ then what is the value of $x ?$

What mathematical operation should come at the place of $?$ in the equation $2 ? 6 - 12 \div 4 + 2 = 11$?

If $x=\sqrt[3]{5}+2,$ then the value of $x^{3}-6 x^{2}+12 x-13$ is

When $\frac{1}{4}$ of a number is subtracted from $\frac{1}{3}$ of the same number,the remainder obtained is $12$. The number is: