1. A solid iron sphere of radius 8 cm is melted down to form solid balls, each of radius 1 cm. Calculate and write how many such balls can be made.

2. The radius of a solid right circular iron rod is 32 cm and its length is 35 cm. If the rod is melted and recast into solid cones each with a radius of 4 cm and height of 28 cm, calculate how many such cones can be made.

3. A solid cylindrical iron rod has a base radius of 32 cm and a height of 35 cm. If the rod is melted and recast into solid cones, each with a radius of 8 cm and a height of 28 cm, how many such cones can be made?

4. A solid sphere with a radius of 3 cm is melted and recast into several small spherical balls, each with a diameter of 0.6 cm. How many such balls are formed?

(a) 1000 (b) 500 (c) 900 (d) 800

5. A solid sphere has a total surface area of 1386 cm². It is melted and reshaped into several right circular cones, each with a radius of 3.5 cm and a height of 6 cm. Find the radius of the solid sphere and determine how many such cones are formed.

6. A vertical hollow cylindrical pipe has an outer radius of 16 cm and an inner radius of 12 cm, with a height of 36 cm. If the pipe is melted and solid cylindrical rods are made from it, each with a diameter of 2 cm and a length of 6 cm, determine how many such solid rods can be produced.

7. A solid lead sphere has a diameter of 14 cm. If this sphere is melted and reshaped into solid spheres with a radius of 3.5 cm, how many such spheres can be formed?

8. "A hollow right circular cylinder has an external diameter of 16 cm and an internal diameter of 12 cm. Its height is 36 cm. If it is melted and recast into solid cylinders, each with a diameter of 2 cm and a height of 6 cm, calculate and write how many such solid cylinders can be made."

9. A solid cylindrical iron rod has a cross-sectional diameter of 16 cm and a length of 1 meter. If this rod is melted and used to form right circular cones, each with a height of 4 cm and a base radius of 5 cm, how many such cones can be made?

10. The diameter of a solid lead sphere is 14 cm. If this sphere is melted, calculate how many solid spheres can be made from it, each having a radius of 3.5 cm.

11. Let’s calculate and see how many solid iron balls of 1 cm diameter can be obtained by melting a solid iron sphere of radius 8 cm.

12. A right circular cone has a base radius of 20 cm and a height of 10 cm. If it is melted down, how many solid spheres of radius 2 cm can be made from it?

(a) 200 (b) 100 (c) 250 (d) 125

13. A solid copper cuboid of length 6.6 decimeters, width 4.2 decimeters, and thickness 1.4 decimeters is melted and recast into solid spheres, each with a diameter of 2.1 decimeters. Calculate how many such spheres can be made and how much metal will be in each sphere (in cubic decimeters).

14. How many solid spheres of radius 5 mm can be made by melting a cylindrical iron rod that is 1 meter long and has a diameter of 4 cm?

15. To make a hollow cylindrical pipe of uniform thickness, a solid iron sphere of radius 6 cm is melted. The pipe has a length of 18 cm and an outer radius of 10 cm. Find the thickness of the pipe.

16. A solid sphere with a radius of 4.2 cm is melted and recast into a solid cylindrical rod with a diameter of 2.8 cm. Find the length of the rod.

17. If a solid iron sphere has a radius of 12 cm, how many cone-shaped objects of 2 cm radius and 3 cm height can be formed by melting the sphere?

18. If a solid iron sphere with a radius of 4 cm is melted, how many solid bullets with a radius of 1 cm can be made?

19. The English translation is: "A solid gold sphere with a radius of 4.2 cm is melted and recast into a solid right circular cylinder with a radius of 2.8 cm. Determine the height (length) of the cylinder."

20. A hemispherical container with an inner radius of 9 cm is completely filled with water. This water is to be transferred into conical bottles, each having a diameter of 3 cm and a height of 4 cm. Calculate how many such bottles are needed to empty the container.

21. A hollow sphere made of lead sheets with a thickness of 1 cm has an outer radius of 6 cm. If this sphere is melted and recast into a solid right circular rod with a radius of 2 cm, calculate the length of the rod.