Trinity Bus Lines wants to maximize the number of passengers it can carry from Far Point to Newtown. Bus A can carry 60 passengers and costs $2,700 per month to run. Bus B can carry 48 passengers and costs $1,800 per month to run. The bus line has a maximum of 12 drivers, and can spend no more than $24,300 per month on running the buses. The bus line wants to purchase at least 1 of Bus A for marketing purposes, and the supplier cannot provide more than seven of Bus A. What is the maximum number of passengers they can carry, and which buses should they purchase? What is the cost to run this fleet for a month? What is the next largest number of passengers they can carry, what buses does it represent, and what is the cost of this other bus fleet for 1 month? Formulate a linear programming model to solve this problem. List the extreme points and determine the solution graphically.