$4.(25)$ A contractor needs to import $100,000$ yd$\text{'}($compacted volume$)$ of soil to build a small earth dam. Two methods of hauling this soil are being considered, as follows Method A Use model XL$37$ scrapers, each having a capacity of $20$yd$.$ These scrapers will need to be pushed by a model BD$12$ bulldozer while they are loading soil at the borrow site, then can travel unassisted to the dam site and deposit the soil there. One BD$12$ will be required for every six scrapers, and the scrapers can work on a cycle time of $30$ min. The labor and equip