if the cost price is 80 % of the selling price , then what is the profit percent ?
"let s . p . = $ 100 c . p . = $ 80 profit = $ 20 profit % = 20 / 80 * 100 = 25 / 6 = 25 % answer is d"
multiply(divide(subtract(const_100, 80), 80), const_100)