a certain quantity of 40 % solution is replaced with 25 % solution such that the new concentration is 35 % . what is the fraction of the solution that was replaced ?
"original quantity = a substituted quantity = b then : ( a * 0.4 + 0.25 * b т а у 0.4 * b ) / a = 0.35 0.4 + ( b / a ) * ( - 0.15 ) = 0.35 b / a = - 0.05 / - 0.15 = 1 / 3 answer : b"
inverse(add(divide(subtract(35, 25), subtract(40, 35)), const_1))