if the cost price of 60 articles is equal to the selling price of 40 articles , then what is the percent profit ?
"let x be the cost price of one article . let y be the selling price of one article . 40 y = 60 x y = 1.5 x the answer is c ."
multiply(const_100, divide(subtract(const_100, divide(multiply(const_100, 40), 60)), divide(multiply(const_100, 40), 60)))