(b) A university needs to purchase 1200 computers. They can purchase computers from three suppliers. Supplier 1 charges 480 per computer plus 4700 for a delivery, Supplier 2 charges 360 per computer plus a delivery charge of 4200, and Supplier 3 charges 270 per computer plus 6500 for a delivery. Supplier 1 can sell at most 550 computers, Supplier 2 can sell at most 850 computers, and Supplier 3 can sell at most 450 computers. Formulate an LP/IP problem to help the university to minimise the cost of purchasing the needed computers. (Do not solve the problem.) [5 marks)