Blue = 1 unit, green = 3 units (3 times blue), red = 1 unit − 45 (45 fewer than blue). The three colours total 760.<br><br>[[model:questions/solutions/q3225.png]]<br><br>• 1 + 3 + 1 = 5 units, − 45 → 760<br>• 5 units → 760 + 45 = 805<br>• 1 unit → 805 ÷ 5 = 161<br>• Green = 3 units → 3 × 161 = 483<br><br>He has 483 green marbles.<br>Check: blue 161 + green 483 + red 116 = 760. ✓