Enormous State University's Business School is buying computers. The school has two models from which to choose, the Pomegranate and the iZac. Each Pomegranate comes with $400 \mathrm{MB}$ of memory and $80 \mathrm{~GB}$ of disk space; each iZac has $300 \mathrm{MB}$ of memory and $100 \mathrm{~GB}$ of disk space. For reasons related to its accreditation, the school would like to be able to say that it has a total of at least $48,000 \mathrm{MB}$ of memory and at least $12,800 \mathrm{~GB}$ of disk space. If the Pomegranate and the iZac cost $\$ 2,000$ each, how many of each should the school buy to keep the cost as low as possible? HINT [See Example 4.]