Your company produces two types of computers, laptops and desktops. Each laptop sold produces a profit of $40 and each desktop produces a profit of $60. You need to consider two separate resources for building laptops and desktops: the amount of labor and assembly time required in the production process. Each laptop requires 4 hours of labor and 12 minutes of assembly time while each desktop requires 6 hours of labor and 4 minutes of assembly time. You have 40 hours of labor available and 60 minutes of assembly time. You can sell every laptop and desktop you produce. Formulate the linear programming model in Excel to solve the problem. Two possible optimal solutions are:

1. produce 0 Laptops and 6.66667 Desktops for a profit of $400
2. produce 3.5714 Laptops and 4.2857 Desktops for a profit of $400.

If you want to produce exactly 5.57 Desktops how many Laptops would you need to produce to keep your new solution optimal?