My teacher taught me a simple equation for these types of problems: (percent of solution × amount of solution) + (percent of solution × amount of solution) = (percent of solution × total amount of solution) in simple terms: %amount + %amount = %total amount We know don't know how much gallons of 60% solution we need so it will be represented as x. We dont know the total amount either so it would have to be both solutions added together so 50 + x. Now lets solve: (0.60)(x) + (0.24)(50) = (0.50)(50 + x) simplify/ distribute 0.6x + 12 = 25 +0.5x get all xs on one side and numbers on other 0.1x + 12 = 25 0.1x = 13 divide both sides by 0.1 to find x x = 130 You need 130 gallons of 60% solution.
