Thirty is 12% of what number ?
30 is 12% of x.\(12\% x=30 \\ \frac{12}{100}x=30 \\ \frac{3}{25}x=30 \\ x=30 \times \frac{25}{3} \\ x=10 \times 25 \\ x=250\)30 is 12% of 250.
\(0.12x=30 \\ /0.12\ \ /0.12 \\ \boxed{x=250}\)
