SOLUTION: 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 260 mil

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: 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 260 mil      Log On


   

Question 1136135: 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 260 milliliters of a dressing that is
11% vinegar. How much of each brand should she use?

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = mm of 5% dressing
Let +b+ = mm of 15% dressing
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(1) +a+%2B+b+=+260+
(2) +%28+.05a+%2B+.15b+%29+%2F+260+=+.11+
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(2) +.05a+%2B+.15b+=+28.6+
(2) +5a+%2B+15b+=+2860+
(2) +a+%2B+3b+=+572+
Subtract (1) from (2)
(2) +a+%2B+3b+=+572+
(1) +-a+-b+=+-260+
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+2b+=+312+
+b+=+156+
and
(1) +a+%2B+156+=+260+
(1) +a+=+104+
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She needs 104 mm of the 1st brand
and 156 mm of the 2nd brand
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check by plugging answers back into (1) and (2)