Answer:
The chef will use 120 milliliters of 11% vinegar, and 80 milliliters of 6% vinegar.
Explanation:
Since a chef is going to use a mixture of two brands of Italian dressing, and the first brand contains 6% vinegar, and the second brand contains 11% vinegar, and the chef wants to make 200 milliliters of a dressing that is 9% vinegar, to determine how much of each brand should she use the following calculation must be performed:
100 x 0.11 + 0 x 0.06 = 11
90 x 0.11 + 10 x 0.06 = 10.5
80 x 0.11 + 20 x 0.06 = 10
70 x 0.11 + 30 x 0.06 = 9.5
60 x 0.11 + 40 x 0.06 = 9
200 x 0.6 = 120
200 x 0.4 = 80
Thus, the chef will use 120 milliliters of 11% vinegar, and 80 milliliters of 6% vinegar.