$${E = \frac{1}{2 \pi \varepsilon_0} \frac{(200\, \mathrm{C})(2)(6,0 \times 10^3\, \mathrm{m}}{(30 \times 10^3\, \mathrm{m})^3} \\ = \underline{\underline{1,6 \times 10^3\, \mathrm{N/C}}}}$$