We have a 10-character sequence where a machine selects each character of the sequence independently and uniformly at random from {a, b, . . . , z}∪{A, B, . . . , Z}∪{0, 1, . . . , 9}. (a) What is the probability that exactly 6 of the characters are digits? (b) What is the expected number of digits in a sequence? (c)What is the variance of the number of digits in a sequence?

We have a 10-character sequence where a machine selects each character of the sequence independently and uniformly at random from {a, b, . . . , z}∪{A, B, . . . , Z}∪{0, 1, . . . , 9}. (a) What is the probability that exactly 6 of the characters are digits? (b) What is the expected number of digits in a sequence? (c)What is the variance of the number of digits in a sequence?

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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