1. (60%) Assume an 8-letter password from the 95 printable ASCII characters is used in a computer system. a. If passwords are chosen by the users, what is the total password population? What is the probability of an adversary guessing a password correctly? b. If passwords are generated automatically by a pseudorandom number generator, what is the total password population? What is the probability of an adversary guessing a password correctly?

Step-by-step explanation:

a. There are 8 characters in the password, and 95 possibilities for each character.  The number of possible combinations is:

95⁸

b. The probability of a password being guessed correctly is:

1 / 95⁸

c. If a number generator is used, there are 10 possibilities for each character.  The number of possible combinations is:

10⁸

d. The probability of a password being guessed correctly is:

1 / 10⁸

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18