The three bags are in the ratio 5 : 1 : 4. The total mass of 20 kg is split into 10 units.<br><br>[[model:questions/solutions/q4503.png]]<br><br>• Total units → 5 + 1 + 4 = 10<br>• 10 units → 20 kg<br>• $$\frac{1}{1}$$ unit → 20 ÷ 10 = 2 kg<br>• Bag B → 1 × 2 = 2 kg<br>• Bag C → 4 × 2 = 8 kg<br>• Difference → 8 − 2 = 6 kg<br><br>The difference between the mass of Bag B and the mass of Bag C is 6 kg.<br>Check: Bag A = 5 × 2 = 10 kg. Total: 10 + 2 + 8 = 20 kg. ✓