A knitting machine can produce 1000 trousers or 3000 shirts (or a combination of the two) each day. The finishing department can handle either 1500 trousers or 2000 shirts (or a combination of the two) each day. The marketing department requires that at least 400 trousers be produced each day. The company's objective is profit maximization. If the profit from the trousers is Rs 40 and that from a shirt is Rs 15, how many of each type should be produced?