jmc

$20\%$ of a number is equal to $\frac{1}{5}$ of that number. Let $n$=the number $\frac{1}{5}n=12$ Multiply both sides by 5 $n=60$ $30\%$ of $n$ is equal to $\frac{3}{10}n=\frac{3}{10}\cdot 60=3\cdot 6=\boxed{18}$