imc

We can replace $2$ and $4$ with $a$ and $b$ respectively. Then substituting with $n$ and $m$ we can get $\frac{a^3{b}^2}{b^3{a}^2}=\frac{a}{b}$ and substitute to get $\frac{2}{4}=\boxed{\frac{1}{2}}$ which is $\boxed{\frac{1}{2}}$