Explanation:

- Calculate the Volume of the Large Ball:

- The volume of a sphere is calculated using the formula: \( \frac{4}{3} \pi r^3 \).

- For the large ball with radius 15 cm:

\(\frac{4}{3} \pi \times 15^3\).

- Calculate the Volume of the Smaller Balls:

- For each smaller ball with radius 5 cm:

\(\frac{4}{3} \pi \times 5^3\).

- Determine How Many Small Balls Fit into the Large One:

- Divide the volume of the large ball by the volume of one small ball to find how many fit:

\(\left(\frac{15^3}{5^3}\right) = \frac{3375}{125} = 27\).

- Options:

- Option 1: 3

- Option 2: 27

- Option 3: 9

- Option 4: 18

- Conclusion: The correct answer is Option 2: 27.