Question

3. (7 points) How many strings of length 7 can be constructed out of the characters wand a such that no two consecutive characters in the string are a? "Bubble"

your answer. (a) 28 (b) 32 O (c) 34 D (d) 36 (е) 42 (f) 78 (g) 128 (h) None of the above

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