Riley's produces two grades of ice cream-creamy and premium. Both are produced by blending two types of dairy mixes. Both dairy mixes contain different amounts of butter fat and skim milk. Their cost per gallon varies accordingly
Dairy Mix Cost Butter Fat Skim Milk
1 0.10 20% 60% Dairy Mix 1 is 60% skim milk
2 0.15 50% 30%
Each gallon of creamy ice cream must contain at least 40% butter fat.
Each gallon of premium must contain at most 50% skim milk.
Monthly demand is for creamy is 800,000 gallons and the demand for premium is 500,000 gallons
How many gallons of each dairy mix must be used to satisfy the monthly demands at a minimum cost?