The Coffee Counter charges $8.00 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 a 22 pound blend that sells for $10.00 per pound

11 lb. of Kenyan French roast and 11 lb. of Sumatran coffee

Explanation:

let K = Kenyan French roast coffee

let S = Sumatran coffee

K + S = 22

8K + 12S = 22 x 10 = 220

K = 22 - S (now we replace K)

8 (22 - S) + 12S = 220

176 - 8S + 12S = 220

4S = 220 - 176 = 44

S = 44 / 4 = 11

K = 22 - 11 = 11