If the height and diameter of a right circular cylinder are 32 cm and 6 cm respectively, then the radius of the sphere whose volume is equal to the volume of the cylinder is :

1. 3 cm

2. 4 cm

3. 4.5 cm

4. 6 cm

A sphere of radius 6 cm is dropped into a cylindrical vessel, partly filled with water. The radius of the vessel is 8 cm. If the sphere is submerged completely, then the surface of the water rises by :

1. 2 cm

2. 3 cm

3. 4 cm

4. 4.5 cm

If a cylindrical rod of iron whose length is 12 times its radius is melted and cast into spherical balls of the same radius, then the number of balls will be :

1. 3

2. 6

3. 9

4. 27