The Coffee Counter charges $10 per pound for Kenyan French Roast coffee and $9 per pound for Sumatran coffee.

How much of each type should be used to make a 20 pound blend that sells for $ 9.50 per pound?

10 pounds of each

Step-by-step explanation:

If K is the amount of Kenyan French Roast coffee, and S is the amount of Sumatran coffee, then the total amount is:

K + S = 20

And the total cost is:

10K + 9S = 9.5*20

10K + 9S = 190

Solving the system of equations, let's substitute:

10K + 9 (20 - K) = 190

10K + 180 - 9K = 190

K = 10

S = 20 - K

S = 10

10 pounds of Kenyan French Roast and 10 pounds of Sumatran coffee should be used to make a 20 pound blend worth $9.50 per pound.