'The Dry-Fruit Company' sells a dry-fruit mixture containing 12 pounds of raisins, 4 pounds of almonds, and 4 pounds of walnuts. If the price of raisins, almonds and walnuts per pound is $a, $b, and $c respectively, what is the price (in dollars) of 1 pound of the dry-fruit mixture?   (a + 3b + 3c) / 5   (3a + b + c) / 5   (a + 4b + 4c) / 20   (12a + b + 4c) / 20   (12a + 4b + c) / 20   Hint Half-n-half Clue