Question 338916
let H=amount of Half and half
Let S = amount of skim milk
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Given:  information for two different equations (total amount, fat content)
1) total: H+S=1gallon
2) amount of fat:  0.12*H+0.0*S=0.02*(1gallon)
                     0.12*H=0.02
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Solve eq 1 for S
S=1-H
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multiply eq 2 by 100 to work with whole numbers and solve for H
12*H=2
H=1/6
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substitute H=1/6 into S=1-H=1-1/6=5/6
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Answer:  1/6 of a gallon of Half and half and 5/6 of a gallon of skim milk
will yield one gallon of 2% fat milk