Jamie is 11 units, Jack 8 units, Josh 7 units. Josh is 4 kg lighter than Jack, which is exactly 1 unit.<br><br>[[model:questions/solutions/q4490.png]]<br><br>• Difference between Jack and Josh → 8 − 7 = 1 unit<br>• $$\frac{1}{1}$$ unit → 4 kg<br>• Jamie → 11 units = 11 × 4 = 44 kg<br><br>Jamie weighs 44 kg.<br>Check: Jack = 8 × 4 = 32 kg, Josh = 7 × 4 = 28 kg. Jack − Josh = 32 − 28 = 4 kg. ✓