Question

A coffee supply store waits until the orders for its special coffee blend reach 100 pounds before making up a batch. Coffee selling for $10.75 a pound is blended with coffee selling for $3.25 a pound to make a product that sells for $5.65 a pound. How much of each type of coffee should be used to make the blend that will fill the orders?

Answer 1

Let x represent the number of pounds of $10.75/lb coffee used in the mix.
.. 10.75x +3.25(100 -x) = 5.65*100 . . . . . . total cost of coffee blend
.. x(10.75 -3.25) = 100*(5.65 -3.25) . . . . . .separate x-terms from non-x terms
.. x = 240/7.5 = 32

32 pounds of $10.75/lb coffee should be used
68 pounds of $3.25/lb coffee should be used