if the price of an article went up by 15 % , then by what percent should it be brought down to bring it back to its original price ?
"let the price of the article be rs . 100 . 15 % of 100 = 15 new price = 100 + 15 = rs . 115 required percentage = ( 115 - 100 ) / 115 * 100 = 20 / 115 * 100 = 17.39 % . answer : a"
multiply(divide(15, add(const_100, 15)), const_100)