Question

clear shine window cleaner is 12% alcohol and sunstearm window cleaner is 30% alcohol. how much of each schould be used to make 90 oz. of a cleaner that is 20% alcohol?

Answer 1

\[0.20={0.12x+0.30(90-x)\over 90}\]\[18=.12x-0.30x+27\]\[0.18x=9\]\[x=50\]so the mixture should contain 50mL of the 12% alcohol and 40 mL of the 20% alcohol