If the cost price of 72 articles is equal to the selling price of 60 articles, then what is the percent profit?  Choose the correct choice from the following options:
A) 10 %
B) 15 %
C) 20 %
D) 25 %
E) 30 %

Rationale: "let x be the cost price of one article . let y be the selling price of one article . 60 y = 72 x y = 1.2 x the answer is c ."
Answer: C