The United States Postal Service (USPS) is responsible for screening packages at mail distribution centers around the country. The USPS is considering the purchase of three types of screening machines for screening packages: Machine A, Machine B, and Machine C. The objective is to maximize the total screening capacity in packages screened per day, given a budgetary allocation of $10 million. Machine A can process 200 packages per hour and costs $1.2 million. Machine A requires 1 postal clerk and can run for 18 hours per day. Machine B can process 150 packages per hour and costs $1.5 million. Machine B requires 2 postal clerks and can run for 16 hours per day. Machine C can process 180 packages per hour and costs $1.8 million. Machine C requires 2 postal clerks and can run for 20 hours per day. There are 100 available postal clerks per day, and the total number of machines must not exceed 30. Using Excel Solver, formulate this problem as an LP to find the number of machines to be purchased to maximize the screening capacity in packages screened per day.