A farmer, in the business of growing fodder for livestock, has 90 acres for planting alfalfa and corn ...

A farmer, in the business of growing fodder for livestock, has 90 acres for planting alfalfa and corn.  The cost of seed per acre is $4 for alfalfa and $6 for corn.  The total cost of labor will amount to $20 per acre for alfalfa and $10 per acre for corn.  The expected income is $110 per acre from alfalfa and $150 per acre from corn.  If the farmer cannot spend more than $480 for seed and $1400 for labor, how many acres of each crop should be planted to obtain the maximum profit?