A farmer has 240 acres to plant. He needs to decide how many acres of corn to plant and how many of oats. He can make $40 per acre profit for corn and $30 per acre for oats. However, the corn takes 2 hours of labor per acre to harvest and the oats only take 1 hour per acre. He only has 320 hours of labor he can invest. To maximize his profit, how many acres of each should he plan