30 is 14.29% of 210.
Step 1: Translate the words into an equation.
30 | is | what percent | of | 210 |
30 | = | x | $ \cdot $ | 210 |
Step 2: Solve for $ x $.
$$ \begin{aligned} 30 &= x \cdot 210 \\[1.2 em] 210 \cdot x &= 30 \\[1.2 em] x &= \dfrac{ 30 }{ 210 } \\[1.2 em] x &= 0.1429 \end{aligned} $$Step 3: Express $ x $ as a percentage.
$$ x = 0.1429 = 0.1429 ~~\cdot~~ 100 \% = 14.29 \% $$