Question 211342
Let x = the number of pounds of coffee at $9.00 per pound, then (20-x) = the number of pounds of coffee at $4.00 per pound. The sum of these two amounts is to equal 20 pounds at $8.25 per pound.
The cost of the x pounds of coffee can be expressed as:
$9(x) and, similarly, the cost of the (20-x) pounds can be expressed as:
$4(20-x) and the sum of these will equal $8.25(20).
Here's the equation:
9x+4(20-x) = 8.25(20)
9x+80-4x = 165
5x+80 = 165
5x = 85
x= = 17 and 20-x = 3.
Juan will to mix 17 pounds of coffee at $9.00 per pound with 3 pounds of coffee at $4.00 per pound to obtain a 20-pound mixture at $8.25 pound.