Boys = 1 unit, girls = 2 units, adults = 4 units. Adults have 2 units more than girls, and that gap is 378.<br><br>[[model:questions/solutions/q3199.png]]<br><br>• Adults − Girls = 2 units → 378<br>• 1 unit → 378 ÷ 2 = 189 (boys)<br>• Children = boys + girls = 189 + 2 × 189 = 567<br><br>There are 567 children at the carnival.<br>Check: adults = 4 × 189 = 756; 756 − 378 (girls) = 378. ✓