Children = 1 unit, adults = 4 units. Altogether 5 units = 860. Adults have 3 units more than children.<br><br>[[model:questions/solutions/q2285.png]]<br><br>• 5 units → 860<br>• 1 unit → 860 ÷ 5 = 172 (children)<br>• Adults − Children = 3 units → 3 × 172 = 516<br><br>There are 516 more adults than children.<br>Check: children 172 + adults 688 = 860, and 688 − 172 = 516. ✓