Explanation:

Let's break down the problem:

- Step 1: Calculate the volume of the large sphere.

- Diameter = 40 cm, so radius = 20 cm.

- Volume of a sphere = \(\frac{4}{3} \pi r^3\).

- Volume of the large sphere = \(\frac{4}{3} \pi (20^3)\).

- Step 2: Calculate the volume of a small sphere.

- Radius = 0.5 cm.

- Volume = \(\frac{4}{3} \pi (0.5^3)\).

- Step 3: Divide the volume of the large sphere by the volume of a small sphere to get the number of small spheres.

- Total number of small spheres = \(\frac{\frac{4}{3}\pi(20^3)}{\frac{4}{3}\pi(0.5^3)}\).

- Calculation:

- \(20^3 = 8000\) and \(0.5^3 = 0.125\).

- Ratio of volumes = \(\frac{8000}{0.125} = 64,000\).

- Conclusion: You can make 64,000 small spheres.

- Correct Answer: Option 3: 64,000