A number is 12 more than one-third of itself. What is the number?

Explanation

1. 01

   $x - \frac{x}{3} = 12$, so $\frac{2x}{3} = 12$.

2. 02

   $x = 12 \times \frac{3}{2} = 18$. Check: $6 + 12 = 18$.