please show work and resons behind it

for this one problem there r (A,B, and C)

1. A company has introduced a process improvement that reduces processing time for each unit, so that output is increased by 25% with less material, but one additional worker required. Under the old process, five workers could produce 60 units per hour. Labor costs are $12/hour, and material input was previously $16/unit. For the new process, material is now $10/unit. For both old and new processes, overhead is charged at 1.6 times direct labor cost. Finished units sell for $31 each. a. 9 pts) What is the productivity in the old process. b. (9 pts) What is the productivity in the new process. c. (7 pts) What increase in productivity is associated with the process improvement