How to calculate quantity of labor employed.

Oz makes lion food out of giraffe and gazelle meat. giraffe meat has 18 grams of protein and 36 grams of fat per pound, while gazelle meat has 36 grams of protein and 18 grams of fat per pound. a batch of lion food must contain at least "46,800" grams of protein and 70,200 grams of fat. giraffe meat costs $1/pound and gazelle meat costs $2/pound. how many pounds of each should go into each batch of lion food in order to minimize costs? hint [see example 2.]