Step 1: Use the weighted average formula:
- Average weight = (Number of students × Average weight) ÷ Total number of students
Step 2: Compute the total weight for each section:
- Total weight of section A = 35 × 38 = 1330 kg
- Total weight of section B = 45 × 42 = 1890 kg
Step 3: Compute the overall average weight:
- Total weight = 1330 + 1890 = 3220 kg
- Total students = 35 + 45 = 80
- Average weight = 3220 ÷ 80 = 40.25 kg
Final Conclusion: The correct answer is (D) 40.25 kg.