Question

The boy : Girl ratio is 4:5. If there are 225 students, how many girls are in the school? answer and proportion answer and proportion breakdown please

Answer 1

$\bf boy:girl\qquad \cfrac{boy}{girl}\qquad 4:5\qquad \cfrac{4}{5}\implies \cfrac{4\cdot \frac{225}{4+5}}{5\cdot \frac{225}{4+5}}\implies \cfrac{4\cdot 25}{\stackrel{girls}{5\cdot 25}}$

so, there are 5 * 25 girls.