Current Electricity: JEE Main 2023 Physics question

A hollow cylindrical conductor has length of 3.14 m, while its inner and outer diameters are 4 mm and 8 mm respectively. The resistance of the conductor is $n\times10^{-3}\Omega$. If the resistivity of the material is $\mathrm{2.4\times10^{-8}\Omega m}$. The value of $n$ is ___________.