Two hollowed metallic spheres centered at the same point form a spherical capacitor. The space between the two spheres is filled with a dielectric material. R₁ - R₂ = 1.5 mm, where R₁ and R ₂ are radii of the outer and inner spheres, respectively. The capacitor has a capacitance of 0.500 nF. Find values of R₁ and R₂.