some of 15 % - intensity red paint is replaced with 25 % solution of red paint such that the new paint intensity is 30 % . what fraction of the original paint was replaced ?
"let total paint = 1 let amount replaced = x 15 ( 1 - x ) + 25 x = 30 x = 3 / 2 answer : d"
divide(subtract(divide(30, const_100), divide(15, const_100)), subtract(divide(25, const_100), divide(15, const_100)))