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.

Find the curved surface area of a right circular cone whose slant height is 10 cm and base radius is 7 cm.

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.

Find the volume of the right circular cone with

(i) radius 6 cm and height 7 cm

(ii) radius 3.5 cm and height 12 cm.