A farmer has 70 acres of land available for planting either soybeans or wheat. The
preparation cost per acre of land is $60 for soybeans and $30 for wheat. Soybeans
require 3 workdays per acre, while wheat requires 4 days. The farmer can make a
profit of $180 per acre of soybeans and $100 per acre of wheat. He cannot spend more
than $1800 in preparation costs and cannot use a total of more than 120 workdays.
How many acres of each crop should be planted to maximize the profit? What is the
maximum profit he can make off of these 70 acres?