Problem: after decreasing 24 % in the price of an article costs rs . 1140 . find the actual cost of an article ?
Rationale: "cp * ( 76 / 100 ) = 1140 cp = 15 * 100 = > cp = 1500 answer : a"
annotated_formula: divide(1140, subtract(const_1, divide(24, const_100)))