1. **Problem 17:** Sebastian's teacher has 8 1/2 square yards of bulletin board paper. Each small bulletin board requires 2 1/4 square yards. We need to find how many small bulletin boards can be covered. 2. Convert mixed numbers to improper fractions: - $8 \frac{1}{2} = \frac{17}{2}$ - $2 \frac{1}{4} = \frac{9}{4}$ 3. Use the formula for how many small boards can be covered: $$\text{Number of boards} = \frac{\text{Total paper}}{\text{Paper per board}} = \frac{\frac{17}{2}}{\frac{9}{4}}$$ 4. Divide fractions by multiplying by the reciprocal: $$\frac{17}{2} \times \frac{4}{9} = \frac{17 \times 4}{2 \times 9} = \frac{68}{18}$$ 5. Simplify the fraction: $$\frac{68}{18} = \frac{34}{9} = 3 \frac{7}{9}$$ 6. Since you cannot cover a partial board fully, they can cover **3 small bulletin boards**. --- 7. **Problem 18:** Zola's teacher has 5 5/6 quarts of hydrogen peroxide. Experiment B requires 1 2/5 quarts per experiment. Find how many times Experiment B can be done. 8. Convert mixed numbers to improper fractions: - $5 \frac{5}{6} = \frac{35}{6}$ - $1 \frac{2}{5} = \frac{7}{5}$ 9. Use the formula: $$\text{Number of experiments} = \frac{\text{Total hydrogen peroxide}}{\text{Per experiment}} = \frac{\frac{35}{6}}{\frac{7}{5}}$$ 10. Divide fractions by multiplying by the reciprocal: $$\frac{35}{6} \times \frac{5}{7} = \frac{35 \times 5}{6 \times 7} = \frac{175}{42}$$ 11. Simplify the fraction: $$\frac{175}{42} = \frac{25}{6} = 4 \frac{1}{6}$$ 12. They can perform Experiment B **4 times** fully. **Final answers:** - Problem 17: 3 small bulletin boards - Problem 18: 4 times Experiment B