Please explain

Consider the following process costing at Smith & Black: (Click the icon to view the company's process costing.) In Process 3-crush and screen limestone rock-300 tons of limestone rock were transported to the plant during March. There was no beginning inventory of rock. During March, 210 tons were crushed, screened, and stocked. At the end of March, 90 tons of rock were 50% crushed and screened. Direct labor and overhead are incurred evenly during the crushing and screening process Requirement 1. Confirm your understanding of the equivalent units concept by computing the equivalent units for material, direct labor, and overhead for Smith & Black. Figure .X Begin by summarizing the flow of physical units and then calculate the output in terms of equivalents units. PROCESS 1 Quarry or Mine Physical Limestone Rock Flow of Production Units Started and completed Work in process, ending inventory PROCESS 2 Transport Units accounted for Rock to Plant Work done to date RESOURCES Direct Material Direct Labor Overhead PROCESS 3 Crush and Screen Limestone Rock PROCESS 4 Finished Cost of Stod Goods Goods Sold Limestone