If 20 % of \(a = b\), then \(b\) % of 20 is the same as:
Answer: A
20 % of \(a = b \Rightarrow \frac{20}{100}a = b.\)
\(\therefore b\) % of \(20 = (\frac{b}{100} \times 20) = (\frac{20}{100}a \times \frac{1}{100} \times 20) = \frac{4}{100}a = 4\)% of \(a\)