Answer:
They must mix
37 pounds of the House Blend
3 pounds of the Kenya Blend.
Explanation:
Let 'x' be House coffe and 'y' be Kenya Coffee. Then:
10.50x + 12.80y = 10.67(40)
Also, we knw that:
x + y = 40
Solving the system of equations above, we have that:
x ≈37.0435 ≈ 37 pounds
y ≈2.95652 ≈ 3 pounds
They must mix
37 pounds of the House Blend
3 pounds of the Kenya Blend.