A lead pencil consists of a cylinder of wood with a solid cylinder of graphite filled in the interior. The diameter of the pencil is 7 mm and the diameter of the graphite is 1 mm. If the length of the pencil is 14 cm, find the volume of the wood and that of the graphite.

A cylindrical roller made of iron is 2 m long. Its inner diameter is 35 cm and the thickness is 7 cm all round. Find the weight of the roller in kg, if 1 cm³ of iron weights 8 g.

Diameter of the base of a cone is 10.5 cm and slant height is 10 cm. Find its curved surface area.

Curved surface area of a cone is 308 cm² and its slant height is 14 cm. Find :

(i) radius of the base

(ii) total surface area of the cone.