Problem: if 5 % more is gained by selling an article for rs . 1000 than by selling it for rs . 20 , the cost of the article is ?
Rationale: "let c . p . be rs . x . then , 5 % of x = 1000 - 20 = 80 x / 20 = 80 = > x = 1600 answer : b"
annotated_formula: divide(subtract(1000, 20), divide(5, const_100))