Explanation:

- To find the mode, we need to identify the most frequently occurring numbers in the data set.

- The given data is: 13, 11, 16, 15, 18, 12, 13, 14, 10, 22, 15, 21, 20, 17, 24.

- Count how often each number appears:

- 13 appears twice.

- 15 appears twice.

- All other numbers appear once.

- Therefore, the modes of the data set are 13 and 15 as they both appear twice.

- The product of the modes is \(13 \times 15 = 195\).

Correct Answer: 4, 195