There is a class of 20 students, S1, S2, S3, . . . , S20. We need to form a study group of at least 2 students. The study group must include at least one of S1, S2 or S3. How many ways do we have forming the study group?

There is a class of 20 students, S1, S2, S3, . . . , S20. We need to form a study group of at least 2 students. The study group must include at least one of S1, S2 or S3. How many ways do we have forming the study group?

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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