Amy operates a coffee kiosk in is blending her special house coffee. She's mixing kenya beans that cost $9 per pound with Columbia beans that cost $7.50 per pound to create a 30 pound one that sells for $8.50 per pound. How many pounds of kenya beans and how many pounds of Colombian beans does amy need to use to create her blend?

12

Step-by-step explanation:

Let K = pounds of Kenyan-French roast

    S = pounds of Sumatran

So 8K + 12S = 10*24 for the total cost.

    K + S = 24 for the total weight.

S = 24 - K, so 8K + 12(24 - K) = 240.

8K + 288 - 12K = 240 or 4K = 48 or K = 12.  So, S = 12.

We would need 12 pounds each to make a blend that would cost $10 per pound.