Consider a source that emits an alphabet with three symbols a, b, c having probability distributions as follows - p(a) = 0.625, p(b) = 0.125, p(c) = 0.25  construct a huffman code and calculate its average code length. (2 points)  for this three-symbol vocabulary, how many huffman codes are possible. what are they? (2 points)  is the code you have defined optimal - give reasons! if not, what can you do to improve upon this. show a solution by an example computing the avg. code length. (6 points)