Ben is 1 unit. Amy is Ben + 5 cm. Chris is Ben + 10 cm (Ben is 10 cm shorter than Chris). The three heights total 465 cm.<br><br>[[model:questions/solutions/q8357.png]]<br><br>• 3 units + 5 + 10 → 465 cm<br>• 3 units → 465 − 15 = 450 cm<br>• 1 unit (Ben) → 450 ÷ 3 = 150 cm<br>• Chris → 150 + 10 = 160 cm<br><br>Chris is 160 cm tall.<br>Check: Ben 150 + Amy 155 + Chris 160 = 465 cm. ✓