National Business Machines manufactures two models of fax machines: A and B. Each model A costs $114 to make, and each model B costs $200. The profits are $23 for each model A and $34 for each model B fax machine. The total number of fax machines demanded per month does not exceed 2100 and the company has earmarked no more than $490,000/month for manufacturing costs. How many units of each model should National make each month in order to maximize its monthly profits? What is the optimal profit?