A company produces three items A, Band C. All these are processed in a central plant.

Production of one unit of A needs 2 hours, while production of a unit of Band C requires, respectively, 3 and 1 hours. The regular plant capacity is 40 hours per week. The marketing department has informed that maximum sales per week of A, Band C is 10, 10 and 12 units, respectively. The chief executive of the company has established the following goals according to their importance:

(i) Avoid any underutilisation of production capacity.

(ii) Meet the order of ABC stores for 7 units of Band 5 units of C per week.

(iii) Avoid the overtime operation of the plant beyond 10 hours.

(iv) Achieve the sales goal of 10 units of A, 10 units of Band 12 units of C.

(v) Minimise the overtime operation as much as possible.

Formulate this as a goal programming problem.