Careful measurements of the electric field at the surface of a box inidcates that the net

Careful measurements of the electric field at the surface of a box inidcates that the net outward flux through the surface of box is `60xx10^(3) Nm^(2) C^(-1)`. Find (i) the net charge inside the box ? (ii) If the net outward flux through the surface of box were zero, could you conclude that there were no charges inside the box ? Explain your answer.