Solve using the graphical method.
Sunnydale Farms has a total of 240 acres of cropland. The farm owner wants to plant this acreage in corn and oats. An acre of corn brings $40 in profit, and an acre of oats gets $30 profit. A total of 320 labor-hours to raise the crops is available. Each acre of corn needs 2 labor-hours, and each acre of oats needs 1 labor-hour. The farm owner wants to optimize the planting of the 240 acres to make maximum profit.