A dishonest grocer professes to sell pure butter at cost price, but he mixes it with adulterated fat and thereby gains 25%. Find the percentage of adulterated fat in the mixture assuming that adulterated fat is freely available?
Options
A) 20%  B) 25%  C) 33.33%  D) 40%  E) 35%
100 * (b + f) - 100 * b = (25/100) * 100 * b   b = 4 * f   Percentage of f = (f / (b + f)) * 100 = (f/5f) * 100 = 20%   20%NSWER:20%
<result>A</result>
A dishonest grocer professes to sell pure butter at cost price, but he mixes it with adulterated fat and thereby gains 25%. Find the percentage of adulterated fat in the mixture assuming that adulterated fat is freely available?