A dishonest dealer professes to sell goods at the cost price but uses a weight of 500 grams per kg, what is his percent? Choose the correct choice from the following options
A) 20 %  B) 25 %  C) 29 %  D) 55 %  E) 100 %

Rationale: "500 - - - 500 100 - - - ? = > 100 % answer : e"
Answer: E