Final Answer:
To make a 20-lb blend selling for $8.40 per pound, use 12 pounds of Kenyan French Roast and 8 pounds of Sumatran coffee.
Step-by-step explanation:
To solve this problem, we can set up a system of equations. Let x represent the pounds of Kenyan French Roast and y ) represent the pounds of Sumatran coffee. The total pounds of the blend is 20, so ( x + y = 20 ).
The cost per pound for the Kenyan coffee is $9.00, and for the Sumatran coffee, it's $8.00. The blend sells for $8.40 per pound, so the average cost is
0 = $168.00. The cost equation is 9x + 8y = 168.
Now, we can solve these equations simultaneously. First, solve for x + y = 20 ) to find ( x = 20 - y ). Substitute this into the cost equation:
9(20 - y) + 8y = 168
Simplify the equation:
180 - 9y + 8y = 168
Combine like terms:
-y = -12
Solve for y :
y = 12
Now that we know y , substitute it back into the equation x + y = 20 to find x :
x + 12 = 20
x = 8
So, the solution is x = 8 and y = 12 , meaning 8 pounds of Kenyan French Roast and 12 pounds of Sumatran coffee should be used to make the 20-lb blend. This combination yields the desired average price of $8.40 per pound.