Answer
$1,000,000$
Work Step by Step
Using the laws of exponents, the given expression, $
(0.25)^3(400^3)
,$ is equivalent to
\begin{array}{l}\require{cancel}
(0.25\cdot400)^3
\\\\=
\left( \dfrac{1}{4}\cdot400 \right)^3
\\\\=
\left( 100 \right)^3
\\\\=
1,000,000
.\end{array}
