b) The customer service office in an automobile maintenance company has 6 technicians to handle the maintenance orders, each one of them works 10 hours daily, and 24 days monthly. Every worker has a regular time hourly rate and an overtime hourly rate of SR24 and SR50, respectively. Due to labor legislations, each technician is not allowed to work more than 280 hours per month. The maintenance service demands for the next six months are given in the table below. Month 1 2 3 4 5 6 Service demand (hours) 1500 1400 1900 2100 1500 1700 Develop the maintenance service's aggregate plan and its total cost for the following scenario: Utilize both the regular working hours and overtime hours; service subcontracting is allowed to a maximum of 150 hours in each month at cost of 75 SR/hour. If the monthly demand cannot be met, there will be a penalty cost of 200 SR/hour for each shortage hour. (15 points)