$$\frac{2}{7}$$ of boys = $$\frac{4}{5}$$ of girls. There are 18 more boys than girls.<br><br>[[model:questions/solutions/q4365.png]]<br><br>• $$\frac{2}{7}$$B = $$\frac{4}{5}$$G ⇒ $$\frac{2B}{7}$$ = $$\frac{4G}{5}$$ ⇒ 10B = 28G ⇒ 5B = 14G ⇒ B : G = 14 : 5<br>• Boys − Girls → 14u − 5u = 9u → 18<br>• 1u → 18 ÷ 9 = 2<br>• Boys → 14 × 2 = 28<br><br>There are 28 boys in the class.<br>Check: Girls = 5 × 2 = 10. $$\frac{2}{7}$$ × 28 = 8. $$\frac{4}{5}$$ × 10 = 8. Equal. ✓