A company makes two models of a product. The times (in hours) required for assembling, painting, and packaging are as follows:
assembly (model a takes 2.5) (model b takes 3); painting (model a takes 2)(model b takes 1); packaging (model a takes .75) and (model b takes 1.25).

The total times available for assembling, painting, and packaging are 4000 hours, 2500 hours, and 1500 hours, respectively. The profits per unit are $50 for model A and $52 for model B. How many of each should be made to obtain a maximum profit?