Problem: a merchant marks his goods up by 30 % and then offers a discount of 20 % on the marked price . what % profit does the merchant make after the discount ?
Rationale: "let the price be 100 . the price becomes 130 after a 30 % markup . now a discount of 20 % on 130 . profit = 104 - 100 4 % answer e"
annotated_formula: subtract(subtract(add(30, const_100), divide(multiply(add(30, const_100), 20), const_100)), const_100)