Malcolm = 11 units, Liam = 9 units. Malcolm is 2 units taller, and that is 34 cm.<br><br>[[model:questions/solutions/q4481.png]]<br><br>• Difference → 11 units − 9 units = 2 units → 34 cm<br>• 1 unit → 34 ÷ 2 = 17 cm<br>• Liam → 9 units = 9 × 17 = 153 cm<br><br>Liam is 153 cm tall.<br>Check: Malcolm 11 × 17 = 187; 187 − 153 = 34. ✓