Suppose � is a positive integer. the (imaginary) sea of babab has islands each of which has an �-letter name that uses only the letters “a” and “b,” and such that for each �-letter name that uses only the letters “a” and “b,” there is an island. for example, if � = 3, then aaa, aab, aba, baa, abb, bab, bba and bbb are the islands in the sea of babab. the transportation system for babab consists of ferries traveling back and forth between each pair of islands that differ in exactly one letter. for example, there is a ferry connecting bab and bbb since they differ only in the second letter. a) how many islands and how many ferry routes are there in terms of �? count the ferry route for both directions as a single ferry route, so for example, the ferry from bab to bbb is the same ferry route. babab does not have much in the way of natural resources or farm land so nearly all food and supplies are provided by the babab all bulk company (babco). the people of babab (bababians) desire easy access to a babco store, where “easy access” means there is a babco store on their own island or on one that they can get to with a single ferry ride. however, babco finds it uneconomical to give the people on one island easy access to two different babco stores, and babco is willing to deny some bababians easy access to a babco store in order to meet this restriction