(d) 64
\(\sqrt[2]{\sqrt[3]{X\times0.000001}}\) = 0.2
\(\Rightarrow\) \(\sqrt[3]{X \times 0.000001}\) = (0.2)2
= 0.04 (Squaring both the sides)
\(\Rightarrow\) x x 0.000001 = (0.04)3 = 0.000064 (on taking the cube of both the sides)
\(\Rightarrow\) x = \(\frac{0.000064}{0.000001}\) = 64.