A computer system uses passwords that contain exactly 4 characters, and each character is 1 of the 3 lowercase letters (a, b, c) or 3 upper case letters (A, B, C) or the 5 odd digits (1, 3, 5, 7, 9). Let Ω denote the set of all possible passwords, and let A and B denote the events that consist of passwords with only letters or only integers, respectively. Determine the number of passwords for Ω. Report the exact number.
Given no. of characters in each password in set Ω is 4
There are 3 + 3 + 5 = 11 choices for each letter of the password (each character can be one of the 3 lowercase letters or one of the set 3 upper case letters or one of the 5 odd digits).
Hence, no. of passwords for Ω
= No. of ways in which each password can be chosen
= 11 * 11 * 11 * 11 = 14641
A computer system uses passwords that contain exactly 4 characters, and each character is 1 of...
A computer system uses passwords that contain exactly 3 characters, and each character is 1 of the 3 lowercase letters (a, b, c) or 3 upper case letters (A, B, C) or the 5 odd digits (1, 3, 5, 7, 9). Let Ω denote the set of all possible passwords, and let A and B denote the events that consist of passwords with only letters or only integers, respectively. Determine the number of passwords for Ω. Report the exact number
A computer system uses passwords that contain exactly 4 characters, and each character is 1 of the 3 lowercase letters (a, b, c) or 3 upper case letters (A, B, C) or the 5 odd digits (1, 3, 5, 7, 9). Let Ω denote the set of all possible passwords, and let A and B denote the events that consist of passwords with only letters or only integers, respectively. Determine the probability that a password contains only numbers given that...
A computer system uses passwords that contain exactly 3 characters, and each character is one of the 26 lowercase letters (a-z) or 26 uppercase letters (A-Z) or 10 integers (0-9). Let Ω denote the set of all possible passwords, and let and denote the events that consist of passwords with only letters or only integers, respectively Suppose that all passwords in 2 are equally likely. Determine the following probabilities. Round your answers to three decimal places (e.g. 98.765). (c) The...
3. A computer system uses passwords that contain exactly eight characters, and each character is one of the 26 lowercase letter (a -z) or 26 uppercase letters (A - Z) or 10 integers (0-9). Let Ω denote the set of all possible passwords. Suppose that all passwords in Ω are equally likely. Determine the probability for each of the following: (a) Password contains all lowercase letters given that it contains only letters (b) Password contains at least 1 uppercase letter...
A company‘s computer system requires passwords to be 7 to 9 characters long, and to consist of uppercase and lowercase letters {A, a, B, b, C, c, . . . , Z, z}, digits {0, 1, 2, 3, . . . , 9} and the special characters {&, #, $, *, +, _}, and to contain at least one special character or digit. How many such passwords are there?
If passwords may contain lower case letters and digits, how many 6-character passwords start with the lower case letter 'a' or ends with the number '3'? Answer:
18. At a certain company, passwords must be from 3-5 characters long and composed of the 26 letters of the alphabet, the ten digits 0-9, and the 14 symbols !,@,#,$,%,^,&,*,().-+,{, and ). (As a note, the password does not REQUIRE at least one character of each type. In other words, it is fine if your password doesn't have any digits or is only special symbols.) a. How many passwords are possible if repetition of characters is allowed? [4 points] b....
A hacker has programmed their computer to generate, uniformly at random, an eight-character password, with each character being either one of 26 lower-case letters (a-z), one of 26 upper-case letters (A-Z) or one of 10 integers (0-9). The hacker wants to infiltrate a website that has 2 million users. Assume, for simplicity, that each user is required to use a unique password. i. What is the expected number of attempts before the hacker successfully generates a user password? ii. What...
Compute the number of passwords of each type below along with how long it would taketo test all possible such passwords if it takes 1 nanosecond to test a password. Report the times in the most convenient human understandable form. In all of these, unless noted otherwise, order matters and repetition of characters is allowed. Passwords of length 8 with any combination of lowercase letters, uppercase letters,and numbers. Passwords that start with a capital letter, have 10 lowercase letters, and...
4: A certain computer program is accessed by entering a user-defined password. If the password a. can contain any lowercase letter, uppercase letter, or digit from 0-9, and must contain 10 characters, how many possible passwords are there if no character can be used more than once? Express your answer as a factorial statement. Is 8 an example of permutations or combinations? b. 4: A certain computer program is accessed by entering a user-defined password. If the password a. can...