Kenyan French Roast Coffee

Question

The Coffee Counter charges $10.00 per pound for Kenyan French Roast coffee and $12.00 per pound for Sumatran coffee.
How much of each type should be used to make anan 18 pound blend that sells for $11.00 per pound?

Answer 1

9 pounds of each

half of 10 and half of 12 gives 18 pounds of 11

9(10) + 9(12) = 18(11)

90 + 108 = 198