If ${2^x} = {4^y} = {8^z}$ and $xyz = 288,$ then ${1 \over {2x}} + {1 \over {4y}} + {1 \over {8z}} = $
$11/48$
$11/24$
$11/8$
$11/96$
Let ${7 \over {{2^{1/2}} + {2^{1/4}} + 1}}$$ = A + B{.2^{1/4}} + C{.2^{1/2}} + D{.2^{3/4}}$, then $A+B+C+D= . . .$
${{{{2.3}^{n + 1}} + {{7.3}^{n - 1}}} \over {{3^{n + 2}} - 2{{(1/3)}^{l - n}}}} = $
${{12} \over {3 + \sqrt 5 - 2\sqrt 2 }} = $
The cube root of $9\sqrt 3 + 11\sqrt 2 $ is
${4 \over {1 + \sqrt 2 - \sqrt 3 }} = $