Answer
$5\sqrt[3]{a^2b}$
Work Step by Step
Using the properties of radicals, the given expression, $
\sqrt[3]{125a^2b}
,$ simplifies to
\begin{array}{l}\require{cancel}
\sqrt[3]{125\cdot a^2b}
\\\\=
\sqrt[3]{(5)^3\cdot a^2b}
\\\\=
5\sqrt[3]{a^2b}
.\end{array}
Note that all variables are assumed to have positive values.