Question

:

Answer 1

Let x = pounds of $12 per pound coffee

then

20-x = pounds of $9 per pound coffee

.

12x + 9(20-x) = 10(20)

12x + 180 - 9x = 200

3x + 180 = 200

3x = 20

x = 20/3

x = 6 and 2/3 pounds of $12 per pound coffee

.

Amount of $9 per pound coffee:

20-x = 20-20/3 = 60/3 - 20/3 = 40/3

or

13 and 1/3 pounds of $9 per pound coffee