The owner of a health-food store sells dried apples for $1.30 per quarter-pound, and dried apricots for $1.60 per quarter-pound. How many pounds of each must he mix together to get 20 lb of a mixture that sells for $1.51 per quarter-pound?

6 pounds of dried apples and 14 pounds of dried apricots

Explanation:

A = dried apples

B = dried apricots

1.3A + 1.6B = 1.51 x 20 = 30.2

A + B = 20

A = 20 - B

Replace A:

1.3 (20 - B) + 1.6B = 30.2

26 - 1.3B + 1.6B = 30.2

0.3B = 30.2 - 26 = 4.2

B = 4.2 / 0.3 = 14

A = 6