The total cost of producing cement consists of the cost of limestone, power, and wages, as well as the profit margin. We are given the prices and the contribution percentages for limestone, power, and wages. Using these percentages, we can calculate the total cost and, from the price data, the operating profit margin:
Operating profit = Price - (Cost of limestone + Cost of power + Cost of wages)
From the data given in the previous table, we find that the operating profit for cement in 2002-03 is 38.5%.