A jewelry store makes necklaces and bracelets from gold and platinum. The store has 20 ounces of gold and 20 ounces of platinum. Each necklace requires 5 ounces of gold and 2 ounces of platinum, whereas each bracelet requires 2 ounces of gold and 4 ounces of platinum. The demand for bracelet is no more than 4.

A necklace earns R1,800 in profit and a bracelet, R1,500. The store wants to determine the number of necklaces and bracelets to make in order to maximize profit.

a. Formulate an integer programming model for this problem.

b. Solve this model by using the computer.