Question

30 is 15% of what number?

Answer 1

$30 =15\% \ of \ x\\ \\ 30= \frac{15}{100}\cdot x \\ \\ 30= \frac{15x}{100} \\ \\ 15x=30\cdot100 \\ \\ 15x=3000\\\\ \boxed{\bold{x=200 }}$

Answer 2

See picture for reply and solution steps.