How many strings of length 9 over the alphabet {a, b, c} are there which contain at least seven consecutive a’s? Hint: Upon writing down a few such strings you will notice that they must take one of three distinct forms (depending on where the consecutive a’s are). Then use the inclusion–exclusion principle.

How many strings of length 9 over the alphabet {a, b, c} are there which contain at least seven consecutive a’s? Hint: Upon writing down a few such strings you will notice that they must take one of three distinct forms (depending on where the consecutive a’s are). Then use the inclusion–exclusion principle.

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

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