The time it takes the staff (who all work at once) to produce the first car is 13 hours and the total staff labor cost is $780/hr. As time goes on, the staff get quicker at producing cars while retaining the same quality level. For the first 100 cars (including the first), it takes an average of 11 hours per car (i.e., it took the staff 1100 hours to produce the first 100 cars). For the next 100 cars, it takes an average of 9 hours per car. For the last 50 cars, it takes an average of 8 hours per car.