Problem: a merchant sells an item at a 20 % discount , but still makes a gross profit of 30 percent of the cost . what percent of the cost would the gross profit on the item have been if it had been sold without the discount ?
Rationale: "original sp = x cost = c current selling price = . 8 x ( 20 % discount ) . 8 x = 1.3 c ( 30 % profit ) x = 1.3 / . 8 * c x = 13 / 8 c original selling price is 1.625 c which is 62.5 % profit answer d"
annotated_formula: subtract(const_100, subtract(subtract(const_100, 20), 30))