If 5% more is gained by selling an article for Rs. 350 than by selling it for Rs. 320, the cost of the article is	Choose the correct choice from the following options:
A) 289 B) 231 C) 200 D) 288 E) 600

Rationale: "explanation : let c . p . be rs . x . then , 5 % of x = 350 - 320 = 30 x / 20 = 30 = > x = 600 answer : e"
Answer: E