Question 148075
In other words, how many gallons of 87 octane and 93 octane should be used to get 15 gallons of octane (why 15?
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Quantity Equation: x + y = 15
Active Ingredient Eq: 87x + 93y = 89*15
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By substitution:
x = 15-y
87(15-y) + 93y = 89*15
6y = 89*15-87*15
y = 30/6
y = 5 (gallons of 93 in the mixture)
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Since x + y = 15, x = 10 (gallons of 87 in the mixture)
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Quantity Equation: x + y = 15
Active Ingredient Eq: 87x + 93y = 89*15
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By elimination:
87x + 87y = 87*15
87x + 93y = 89*15
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Subtract 1st from 2nd to get:
6y = 30
y = 5
Then x = 10
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Cheers,
Stan H.