Suppose that the number of worker-hours required to distribute new telephone books to x% of the households in a certain rural community is given by the function W(x)=250x/(400−x).
(a) What is the domain of the function W? (Give the domain in interval notation. If the answer includes more than one interval write the intervals separated by the "union" symbol, U)
(b) For what values of x does W(x) have a practical interpretation in this context?
(c) How many worker-hours were required to distribute new telephone books to the first 70% of the households?
(d) How many worker-hours were required to distribute new telephone books to the entire community?
(e) What percentage of the households in the community had received new telephone books by the time 3 worker-hours had been expended?