8 is 20% of 40.
Step 1: Translate the words into an equation.
8 | is | what percent | of | 40 |
8 | = | x | $ \cdot $ | 40 |
Step 2: Solve for $ x $.
$$ \begin{aligned} 8 &= x \cdot 40 \\[1.2 em] 40 \cdot x &= 8 \\[1.2 em] x &= \dfrac{ 8 }{ 40 } \\[1.2 em] x &= 0.2 \end{aligned} $$Step 3: Express $ x $ as a percentage.
$$ x = 0.2 = 0.2 ~~\cdot~~ 100 \% = 20 \% $$