A source produces independent symbols from an alphabet of three letters. Each source symbols can be A,B or C with respective probability 0.5, 0.25 and 0.25. (a) What is the source entropy H? (b) Find a Huffman code for the individual letters of the source alphabet. What is the average number of bits per symbol for this code? (c) You are asked to design a code for blocks of two symbols from the source at a time. The alphabet for this extended source is of size 9.