A uniform volume charge density of

A uniform volume charge density of 80 C/m3 is present throughout the
region 8 mm < r < 10 mm. Let = 0 for 0 < r < 8 mm. (a) Find the total charge inside the spherical surface r = 10 mm. (b) Find Dr at r = 10 mm. (c) If there is no charge for r > 10 mm, find Dr at r =20 mm.