12 spheres of the same size are made by melting a solid cylinder of 16cm diameter and 2cm height. Then, the diameter of each sphere is

A hemisphere of lead of radius 8cm is cast into a right circular cone of base radius 6cm. Determine the height of the cone.

Three cubes of iron whose edges are 6cm, 8cm and 10cm are melted and formed into a single cube. Then the edge of the new cube is

The length of a cold storage is double its breadth. Its height is 3m. The areas of its four  walls is 108m². Find its volume.

Spherical ball of diameter 21cm is melted and recasted into cubes, each of side 1cm. Find the numbers of cubes thus formed.

Volumes of two spheres are in the ratio 64:27. The ratio of their surface area is

Three sphere of radii 3cm, 4cm and 5cm are melted to form a new sphere. Then, the radius of the new sphere is

The diameter of a garden roller is 1.4m and it is 2m long. How much area will it cover in 5 revolutions?  (Take Π=22/7)

The depth of a bucket is 42cm and the diameter if its top and bottom are 30cm and 10cm respectively. Then, the volume of the bucket is

A spherical ball of lead 3 cm in diameter, is melted and recast into three spherical balls. The diameter of two of these balls are 1.5 cm and 2 cm respectively. Then, the diameter of the third ball is