Solve : ( 0.050.25 + 0.250.05 )^3 =\, ?

Answer: Option C

$$\begin{array}{rl}& {\left(\frac{0.05}{0.25}+\frac{0.25}{0.05}\right)}^3\\ & ={\left(\frac{5}{25}+\frac{25}{5}\right)}^3\\ & ={\left(\frac{1}{5}+5\right)}^3\\ & ={\left(\frac{26}{5}\right)}^3\\ & ={\left(5.2\right)}^3\\ & =140.608\approx 140.6\end{array}$$