A mini zoo is engaged in animal breeding where the animals require three different nutrients everyday. The minimum requirement for calories is 216g per day while the minimum requirement for protein and sodium is 72g and 200mg per day, respectively. Zookeeper would like to give the animals a mix of product Alpha and product Beta to provide the minimum nutritional requirement. The product cost per unit of Alpha is Rp. 40 and the product cost per unit of Beta is Rp. 80. A unit of product Alpha contains 72g of calories, 6g of protein and 40mg of sodium. While a unit of product Beta contains 12g, 24g and 20mg of calories, protein and sodium, respectively.
If a small change occur for the product cost of Alpha; in what small range of the change could remains the current optimal?
On the basis of (1), compute the objective coefficient range for product Alpha.