Roddy
20

# there are 12 boys and 10 girls in the gym class. If 6 more boys joined , how many more girls are needed to stay at the same ratio.

$\frac{12}{10}= \frac{18}{x}$ cross multiply 12x=180 divide both sides by 12 x=15 if their is 10 girls, then you need 5 more to keep the ratio.