Consider this problem.

To determine how many \( 1 \frac{7}{8} \) kilogram books can fit into a box that holds \( 28 \frac{1}{8} \) kilograms, you would divide. Specifically, you need to divide the total weight the box can hold by the weight of each book.

### Calculation Steps:
1. Convert the mixed numbers to improper fractions:
- \( 28 \frac{1}{8} \) can be converted as follows:
\[
28 \frac{1}{8} = \frac{28 \times 8 + 1}{8} = \frac{224 + 1}{8} = \frac{225}{8}
\]
- \( 1 \frac{7}{8} \) can be converted similarly:
\[
1 \frac{7}{8} = \frac{1 \times 8 + 7}{8} = \frac{8 + 7}{8} = \frac{15}{8}
\]

2. Now, divide the total weight by the weight of one book:
\[
\frac{225/8}{15/8} = \frac{225}{8} \times \frac{8}{15} = \frac{225}{15}
\]

3. Simplifying \( \frac{225}{15} \):
\[
\frac{225}{15} = 15
\]

### Conclusion:
You will **divide** to solve this problem, and the box can hold **15 books**.

### Final Response:
- **Will you multiply or divide to solve this problem?**
**Divide**

- **How many books will it hold?**
**15 books**