Question

A chef is going to use a mixture of two brands of Italian dressing. The first brand contains 5% vinegar, and the second brand contains 15% vinegar. The chef wants to make 240 millimeters of a dressing that is 13% vinegar. How much of each brand should she use?

Answer 1

48 mL 5% vinegar, 192 mL 15% vinegar

Explanation:

If x is volume of 5% vinegar, and y is volume of 15% vinegar, then:

x + y = 240

0.05 x + 0.15 y = 0.13 (240)

Solve with substitution:

0.05 x + 0.15 (240 − x) = 0.13 (240)

0.05 x + 36 − 0.15 x = 31.2

0.10 x = 4.8

x = 48

y = 192