The Kleenglass Corporation makes a dishwasher that has excellent cleaning power. This dishwasher uses less water than most competitors, and it is extremely quiet. Orders have been received from several retails stores for delivery at the end of each of the next 3 months, as shown below:

Month No. of units

June 195

July 215

August 205

Due to limited capacity, only 200 of these can be made each month on regular time, and the cost is $300 each. However, an extra 15 units per month can be produced if overtime is used, but the cost goes up to $325 each. Also, if there are any dishwashers produced in a month that are not sold in that month, there is a $20 cost to carry this item to the next month. Use the simplex method of linear programming to determine how many units to produce in each month on regular time and on overtime to minimize the total cost while meeting the demands.