20% of a = b, then b% of 20 is the same as ________ of a:

8% 4% 40% 80%

4%

ATQ,  20% a = b  \(\frac{1}{5}\) a = b \(\frac{a}{b}\)   = \(\frac{5}{1}\) So, b% × 20 = 1% × 20 = 0.2 Then, \(\frac{0.2}{a}\) × 100 =  \(\frac{0.2}{5 }\) × 100 = 4%