1. **Stating the problem:** We have four subproblems involving multiplication and division with decimals, and a word problem about buying fruit with prices per kilogram. 2. **Subproblem a:** Calculate $4.9 \times 10.2$. - Multiply as usual: $4.9 \times 10.2 = 49.98$. 3. **Subproblem b:** Calculate $62.1 \div 3.3$ and compare with $7.5 \div 5$. - Calculate $62.1 \div 3.3 = 18.8181... \approx 18.82$. - Calculate $7.5 \div 5 = 1.5$. - Since $18.82 \neq 1.5$, the equality $62.1 : 3.3 = 7.5 : 5$ is false. 4. **Subproblem c:** Given $12.1 : 5.3 = ? : ? = ?$. - The problem is incomplete; we cannot solve without more information. 5. **Subproblem d:** Given $4.7 : 0.9 = ? : ? = ?$. - Similarly, incomplete data prevents solving. 6. **Word problem:** Stian buys 1.8 kg clementines at 13.90 per kg, 18.90 per kg (likely a correction), and 3 kg apples at 28.50 per kg. - We assume the clementines cost 13.90 per kg. - Calculate cost of clementines: $1.8 \times 13.90 = 25.02$. - Calculate cost of apples: $3 \times 28.50 = 85.50$. - Total cost estimate: $25.02 + 85.50 = 110.52$. 7. **Summary:** - a) $49.98$ - b) $62.1 : 3.3 \neq 7.5 : 5$ - c) and d) incomplete data - Fruit cost approximately $110.52$. This completes the first problem fully and addresses the word problem with an estimate.