Consider strings of length n over the set {a, b, c, d}.a.
Chapter 9, Problem 22E(choose chapter or problem)
Problem 22E
Consider strings of length n over the set {a, b, c, d}.
a. How many such strings contain at least one pair of adjacent characters that are the same?
b. If a string of length ten over {a, b, c, d} is chosen at random, what is the probability that it contains at least one pair of adjacent characters that are the same?
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