A certain product has been effectively managed in the past, according to its managers. The previous technique used the economic production quantity model, and resulted in an optimum lot size of 100. For this product, setup time is directly proportional to setup cost, and setup time is currently 40 minutes per batch. How much must setup time decline in order for the lot size to fall to 50 units? 25 units? 10 units? Explain how you determined the declines in setup time you calculated.