25. A company has two grades of inspectors 1 and 2, who are to be assigned for a quality control inspection.

It is required that at least 2,000 pieces be inspected per 8- hour day. A grade 1 inspector can check pieces at the rate of 40 per hour, with an accuracy of 97 percent. A grade 2 inspector can check at the rate of30 pieces per hour, with an accuracy of95 percent.

The wage rate of grade 1 inspector is Rs 5 per hour while that of a grade 2 inspector is Rs 4 per hour. An error made by inspector costs Rs 3 per piece. There are only 9 grade 1 inspectors and 11 grade 2 inspectors available in the company. The company wishes to assign work to the available inspectors so as to minimise the total cost of inspection. Formulate this problem as a linear programming model and solve it by using graphical method.