Problema Solution
window cleaner has 12% alcohol an sunstream window has 30% alcohol. how much of each should be used to make 90 oz cleaner that is 20% alcohol
Answer provided by our tutors
well, i used trial and error...
(0.12 * ClearShine) + (0.30 * Sunstream) = (0.20 * 90 oz)
So, 0.2 * 90 means you need 18 oz of alcohol in the final solution. Then you do a little guess work. You know that you need more ClearShine because the final solution has leess alcohol than Sunstream. So, lets guess 50 oz of Clearshine. 0.12 * 50 = 6 oz. Then, since we've already used 50 oz, we'll say 40 oz. of Sunstream. 0.30 * 40 = 12 oz. Add these up, 6 + 12 = 18, so we know we've chosen the correct amounts.
50 oz ClearShine and 40 oz Sunstream