Example 11: Three grades of coal A, B and C contains phosphorus and ash as impurities. In a particular industrial process, fuel up to 100 ton (maximum) is required which could contain ash not more than 3% and phosphorus not more than 0.03%. It is desired to maximize the profit while satisfying these conditions. There is an unlimited supply of each grade. The percentage of impurities and the profits of each grade are as follows: Coal A B C Phosphorus .02 .04 .03 Ash 3.0 2.0 5.0 Profit in 12.00 15.00 14.00 You are required to formulate the Linear programming model to solve it by using simplex method to determine optimal product mix and profit. [Nov 05]