A man buys an article for $100. and sells it for $130. Find the gain percent?	Options:  A) 10 %  B) 15 %  C) 25 %  D) 20 %  E) 30 %

Rationale: "c . p . = $ 100 s . p . = $ 130 gain = $ 30 gain % = 30 / 100 * 100 = 30 % answer is e"
Answer: E