Three-fifth of the square of a certain number is $126.15$. What is the number?

The value of $\frac{\sqrt{80}-\sqrt{112}}{\sqrt{45}-\sqrt{63}}$ is

$\frac{\sqrt{0.0009}}{\sqrt{0.01}} = ?$

In the following questions,two equations numbered $I$ and $II$ are given. You have to solve both the equations and give the answer.
$I$: $\sqrt{25 x^{2}} - 125 = 0$
$II$: $\sqrt{361} y + 95 = 0$

Which of the following numbers,wherein some of the digits have been suppressed by symbols,can possibly be the perfect square of a $3$-digit odd number?

If $x=\frac{\sqrt{3}+1}{\sqrt{3}-1}$ and $y=\frac{\sqrt{3}-1}{\sqrt{3}+1},$ then the value of $(x^{2}+y^{2})$ is