A meat processing plant uses two machines, a meat slicer and a meat packer, to make their hams and pork ribs. To produce one batch of hams requires 4 hours on the meat slicer and 2.5 hours on the meat packer. To produce one batch of pork ribs requires 2 hours on the meat slicer and 3.5 hours on the meat packer. Each machine runs for at most 4000 hours per year. If the profit per batch of hams is $150 and the profit per batch of pork ribs is $300, how many batches of each should be made to maximize profit?