20. A rural clinic hires its staff from nearby cities and towns on a part-time basis. The clinic attempts to have a general practitioner (GP), a nurse and an internist on duty during at least a portion of each week. The clinic has a weekly budget of Rs 1,200. A GP charges the clinic Rs 40 per hour, a nurse charges Rs 20 per hour, and an internist charges Rs 150. The clinic has established the following goals in order of priority.

(i) A nurse should be available for at least 30 hours per week.

(ii) The weekly budget of Rs 1,200 should not be exceeded.

(iii) A GP or internist should be available at least 20 hours per week.

(iv) An internist should be available at least 6 hours per week.

Formulate a goal programming model for determining the number of hours to hire each staff member in order to satisfy the various goals. (MBA, Delhi, March 2004)