he ratio between the sale price and the cost price of an article is 3 : 1 . what is the ratio between the profit and the cost price of that article ?
"let c . p . = rs . x and s . p . = rs . 3 x . then , gain = rs . 2 x required ratio = 2 x : x = 2 : 1 . answer : a"
inverse(subtract(const_1, divide(1, 3)))