Question 624995
Cream costs $10 per gallon.  Milk costs $3 per gallon. 

9 gallons of milk was mixed with 2 gallons of cream.

What is the cost of 1 gallon of this mixture?
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9 + 2 = 11 gallons
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9*3 + 2*10 = $47 for 11 gallons
--> $47/11 per gallon
=~ $4.27/gallon