A chef is going to use a mixture of two brands of Italian dressing. The first brand contains 7% vinegar, and the second brand contains 12% vinegar. The chef wants to make 270 milliliters of a dressing that is 9% vinegar. How much of each brand should she use?

Answer: There is 162 ml of first brand and 108 ml of second brand.Step-by-step explanation:Since we have given that Percentage of vinegar that the first brand contains = 7%Percentage of vinegar that the second brand contains = 12%Percentage of vinegar in mixture = 9%Total amount of dressing = 270 mlWe will use "Mixture and Allegation":First brand                  Second brand      7%                                12%                        9%--------------------------------------------------------12%-9%             :                9%-7%  3%                   :                    2%So, ratio of first brand to second brand in a mixture is 3:2.So, Amount of first brand she should use is given by[tex]\dfrac{3}{5}\times 270\\\\=162\ ml[/tex]Amount of second brand she should use is given by[tex]\dfrac{2}{5}\times 270\\\\=108\ ml[/tex]Hence, there is 162 ml of first brand and 108 ml of second brand.