SOLUTION: Fred mixes snack mix with mixed nuts to make trail mix. The snack mix is 10% peanuts; the mixed nuts are 35% peanuts. How many ounces of each should he combine to make 8 ounces of

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: Fred mixes snack mix with mixed nuts to make trail mix. The snack mix is 10% peanuts; the mixed nuts are 35% peanuts. How many ounces of each should he combine to make 8 ounces of       Log On

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Question 275882: Fred mixes snack mix with mixed nuts to make trail mix. The snack mix is 10% peanuts; the mixed nuts are 35% peanuts. How many ounces of each should he combine to make 8 ounces of trail mix that is 20% peanuts?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
In words:
(ounces of peanuts in 10% mix + ounces of peanuts in 35% mix)/(ounces of mix) = 20%
Let a = ounces of 10% mix needed
Let b = ounces of 35% mix needed
%28.1a+%2B+.35b%29%2F8+=+.2
(1) a+%2B+b+=+8
+.1a+%2B+.35b+=+1.6
(2) 10a+%2B+35b+=+160
Multiply both sides of (1) by 2
and subtract from (2)
(2) 10a+%2B+35b+=+160
(1) -10a+-+10b+=+-80
25b+=+80
b+=+3.2
and, since
a+%2B+b+=+8
a+=+8+-+3.2
a+=+4.8
4.8 ounces of 10% mix and 3.2 ounces of 35% mix are needed
check:
+.1a+%2B+.35b+=+1.6
+.1%2A4.8+%2B+.35%2A3.2+=+1.6
.48+%2B+1.12+=+1.6
1.6+=+1.6
OK