A dishonest dealer professes to sell goods at the cost price but uses a weight of 920 grams per kg, what is his percent?  Pick one
A) 22 % B) 25 % C) 77 % D) 99 % E) 8.7 %

Rationale: "920 - - - 80 100 - - - ? = > 8.7 % answer : e"
Answer: E