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

Correct option is C

Given:
20% of a = b
Solution:
a × 20/100 = b
a × 1/5 = b
a × 1/b = 5
a/b= 5/1
a : b = 5 : 1
Let a = 5 and b = 1
b% of 20 = a% of x
1 % × 20 = 5% × x
20 = 5x
x = 4
therefore, the correct answer is (c).