18 is 15% of 120.
Step 1: Translate the words into an equation.
18 | is | what percent | of | 120 |
18 | = | x | $ \cdot $ | 120 |
Step 2: Solve for $ x $.
$$ \begin{aligned} 18 &= x \cdot 120 \\[1.2 em] 120 \cdot x &= 18 \\[1.2 em] x &= \dfrac{ 18 }{ 120 } \\[1.2 em] x &= 0.15 \end{aligned} $$Step 3: Express $ x $ as a percentage.
$$ x = 0.15 = 0.15 ~~\cdot~~ 100 \% = 15 \% $$