if the cost price of 55 articles is equal to the selling price of 50 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 . 50 y = 55 x y = 1.1 x the answer is b ."
multiply(const_100, divide(subtract(const_100, divide(multiply(const_100, 50), 55)), divide(multiply(const_100, 50), 55)))