Problem: if the selling price of 50 articles is equal to the cost price of 35 articles , then the loss or gain percent is :
Rationale: "c . p . of each article be re . 1 . then , c . p . of 50 articles = rs . 50 ; s . p . of 50 articles = rs . 35 . loss % = 15 / 50 * 100 = 30 % answer c"
annotated_formula: subtract(50, 35)