If $a * b = 2a - 3b + ab$,then $3 * 5 + 5 * 3$ is

Which of the following statement$(s)$ is/are $TRUE$?
$I.$ $\sqrt{12} > \sqrt[3]{16} > \sqrt[4]{24}$
$II.$ $\sqrt[3]{25} > \sqrt[4]{32} > \sqrt[6]{48}$
$III.$ $\sqrt[4]{9} > \sqrt[3]{15} > \sqrt[6]{24}$

If $\sqrt{7 \sqrt{7 \sqrt{7 \sqrt{7 \cdots}}}} = (343)^{y-1}$,then $y$ is equal to

Evaluate $\frac{(2.39)^{2}-(1.61)^{2}}{2.39-1.61}$

If $3x + \frac{3}{x} = 1$,then $x^{3} + \frac{1}{x^{3}} + 1$ is

If $\frac{x^{24}+1}{x^{12}}=7$,then find the value of $\frac{x^{72}+1}{x^{36}}$.