Problem: if the selling price of 100 articles is equal to the cost price of 63 articles , then the loss or gain percent is :
Rationale: "let c . p . of each article be re . 1 . then , c . p . of 100 articles = rs . 100 ; s . p . of 100 articles = rs . 63 . loss % = 37 / 100 * 100 = 37 % answer : e"
annotated_formula: subtract(100, 63)