Girls are 1 unit; boys are twice as many, so 2 units. Altogether that is 3 units = 1740 pupils.<br><br>[[model:questions/solutions/q3184.png]]<br><br>• Girls + Boys = 3 units → 1740<br>• 1 unit → 1740 ÷ 3 = 580<br><br>There are 580 girls.<br>Check: 580 girls + 1160 boys = 1740 pupils. ✓