barbara produces plastic cups using a process that requires only labor and plastic as inputs and has constant returns to scale. with the process she is currently using, a laborer can turn out 40 cups an hour. the wage rate is $10 per hour. the plastic in a cup costs barbara $.20. she has no other costs besides labor and plastic. barbara faces a perfectly competitive market for plastic cups, and she decides that she is maximizing profits when she makes 400 cups an hour. what is the market price of cups?
