A four-worker crew was assigned to install plumbing in a house. To accelerate the work, it was suggested that two additional crews (consisting of four workers each) be assigned to do the work. - If the initial estimate was that the four-worker crew could complete the work in 12 days, what is the best estimate of the completion time with the additional crews? - What is the estimated labor cost of the change in worker assignments if all workers are paid $20 per hour?