Question: Edward the plumber is replacing a pipe in a bathroom wall. He needs to use 40 feet of copper pipe to complete the job. For every 5 feet of pipe, Edward must use one tightening bolt, and for every bolt, he uses two washers. He buys a bag of 20 washers for the job. After he completes the bathroom job, how many washers will be remaining in the bag? Think carefully first, then make a decision:
If Edward needs to use 1 bolt per every five feet of piping, then for a job requiring 40 - feet of piping, he will use 40 / 5 = 8 tightening bolts. If for every 1 bolt he uses two washers, then he will need 8 * 2 = 16 washers to complete the job. if he buys a bag containing 20 washers, and removes 16, he will have 20 - 16 = 4 washers remaining in the bag. So the answer is 4.