A contractor is planning a new housing development consisting of colonial, split-level, and ranch-style houses. A colonial house requires ½ acre of land, $60,000 capital, and 4,000 labor-hours to construct, and returns a profit of $20,000. A split-level house requires ½ acre of land, $60,000 capital, and 3,000 labor-hours to construct, and returns a profit of $18,000. A ranch house requires 1 acre of land, $80,000 capital, and 4,000 labor-hours to construct, and returns a profit of $24,000. The contractor has 30 acres of land, $3,200,000 capital, and 180,000 labor-hours available. How many houses of each type should be constructed to maximize the contractor’s profit? What is the maximum profit?