A construction site requires a minimum of 2000 cubic meters of sand and gravel mixture. The mixture must contain no less than 1000 cubic meters of sand and no more than 1200 cubic meters of gravel. Materials may be obtained from two sites: 20% of sand and 80% gravel from site 1 at a delivery cost of $6 per cubic meter and 60% sand and 40 gravel from site 2 at a delivery cost of $4 per cubic meter. Complete the previous question and then report the amount of material from site 1 and from site 2 that minimizes the cost of the project: 6000 x cubic meters of the sand and gravel mixture from site 1 6000 x cubic meters of the sand and gravel mixture from site 2 Purchasing the above quantities minimizes the cost of the project at C] dollars