A farmer has 400 acres available for cultivating crops A, B, and C. He
has a total of $11,200 for cultivation costs and a maximum of 13,200 hours of
labor available. For each acre, the cost and labor required for cultivation are
as follows: crop A, $30 and 20 hours; crop B, $40 and 30 hours; and crop C, $20
and 40 hours. How many acres of each crop should the farmer plant if he wishes
to utilize all his resources?