The management of an industry, in which some machines are under employed, considers the case to produce products 1,2,3 and 4 during the idle time of the machines. This time is estimated at 500,350,150 and 200 machine hours per week for machine types A,B,C and D respectively. The machine hours needed for the production of each product unit are presented in the table below. The sales department predicts that the profit from the sale of each unit of products 1, 2, 3 and 4 is RM 30,RM12,RM25 and RM 18 respectively. Which mathematical model should solve the industry to identify the quantities of products that should be produced, in order to maximize the net profit