1. Mathematics
2. Algebra
3. Basic Algebra
4. 184441

A computer system uses passwords constructed from the 26 letters (a to z) or 10 integers (0 to 9). Suppose there are 10000 users on the system with unique passwords. A hacker randomly selects (with replacement) passwords from the potential set.

A) There are 9900 users with unique 6 character passwords on the system and the hacker randomly selects 6 character passwords. What is the mean and standard deviation of the number of attempts before the hacker selects a user password?

B) Suppose there are 100 users with unique 3 character passwords on the system and the hacker randomly selects 3 character passwords. What is the mean and standard deviation of the number of attempts before the hacker selects a user password?

C) Which system is more secure the 6 character or the 3 character password protected system?