Based on Charnes and Cooper (1955). Alex Cornby makes his living buying and selling corn. On January 1, he has 500 tons of corn and $10,000. On the first day of each month, Alex can buy corn at the following prices per ton: January, $300; February, $350;

March, $400; April, $500. On the last day of each month, Alex can sell corn at the following prices per ton: January, $250; February, $400; March, $350;

April, $550. Alex stores his corn in a warehouse that can hold 1000 tons of corn. He must be able to pay cash for all corn at the time of purchase. Determine how Alex can maximize his cash on hand at the end of April.