If $\frac{\sqrt{5+x}+\sqrt{5-x}}{\sqrt{5+x}-\sqrt{5-x}}=3,$ then what is the value of $x?$

The value of $\frac{1}{1 \cdot 2 \cdot 3} + \frac{1}{2 \cdot 3 \cdot 4} + \frac{1}{3 \cdot 4 \cdot 5} + \frac{1}{4 \cdot 5 \cdot 6}$ is:

$\left[\frac{8(3.75)^{3}+1}{(7.5)^{2}-6.5}\right]$ is equal to

Choose the incorrect relation$(s)$ from the following:
$(i)$ $\sqrt{6}+\sqrt{2}=\sqrt{5}+\sqrt{3}$
$(ii)$ $\sqrt{6}+\sqrt{2}<\sqrt{5}+\sqrt{3}$
$(iii)$ $\sqrt{6}+\sqrt{2}>\sqrt{5}+\sqrt{3}$

If the square of the sum of three positive consecutive natural numbers exceeds the sum of their squares by $292$,then what is the largest of the three numbers?

What is the unit's digit of $125^{125} + 216^{216}$?