Answer
(a) 6
(b) 4
(c) 1/4
Work Step by Step
(a) $\frac{\sqrt{216}}{\sqrt{6}}=\sqrt{\frac{216}{6}}=\sqrt{36}=6$
(b) $\sqrt[3]{2}\sqrt[3]{32}=\sqrt[3]{64}=4$
(c) $\displaystyle \sqrt[4]{\frac{1}{4}}\sqrt[4]{\frac{1}{64}}=\sqrt[4]{\frac{1}{256}}=\frac{1}{\sqrt[4]{256}}=\frac{1}{4}$