2.14. Let S={s1,s2,,s6} and T={a,b,c}, and suppose that a code is defined by s1a,s2ba,s3bb1s4bc,s5ca,s6cb. Write down the generating function Q1(x) and hence (by algebraic means) find Q2(x). 2.15. In the previous exercise, what does the coefficient of x4 in Q2(x) represent? Verify your answer by making a list of the corresponding elements of S