How many six-symbol computer passwords can be formed using the letters A to J and the digits 2 to 5? passwords
Find the number of combinations.
8C4
Ans.
A to J is 10 Letters
2 to 5 is 4 numbers
--> 14 Choices
======================
--> 14^6
= 7529536 passwords if it's not case sensitive, ie, if a = A, b =
B, etc
8C4=8!/4!*(8-4)!
=8*7*6*5*4!/4!*4*3*2*1
=70
How many six-symbol computer passwords can be formed using the letters A to J and the...
12. Computer system #1 requires logon passwords to be eight upper-case letters. How many different passwords are there for system #1? Computer system #2 requires logon passwords to be eight characters, which may be upper or lower-case letters, the numbers 0 through 9, and the characters $, #, and %. How many different passwords are there for system #2?
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:
A password consists of three letters followed by a two-digit number. (a) How many passwords are possible if there are no restrictions? 1757600 (b) How many passwords are possible if none of the letters or digits can be repeated? (c) What is the probability of guessing the password in one trial if there are no restrictions? O A. 0.0000007123 O B. 0.0000005690 O C. 0.2 O D. 0.798816568
How many different passwords of size 6 can be formed using English alphabet characters if the first letter must be a capital letter and the remaining letters must be lower case? a) 26 * C(25, 5) b) P(26, 5) c) 26 * P(26, 5) d) 26 * C(26, 5) e) P(26, 6)
A password consists of one letter followed by a five-digit number. A) How many passwords are possible if none of the letters or digits can be repeated? B) What is the probability of guessing the password in one trial if there are no restrictions? (To find the probability use the definition of classical probability.)
i. How many 5-letter passwords (letters may be repeated) can be created from the monkey type- writer from Q1 if it is forbidden for a password to begin and end with the same letter? Answer: 11. Using the monkey typewriter from Q1, how many 8-letter words are there consisting of 8 distinct letters that contain the word 'APE' (as 3 consecutive) letters within the 8-letter word? Answer: iii. Suppose that a group of 9 inhabitants of the Island of Knights...
1. (a) (i) How many different six-digit natural numbers may be formed from the digits 2, 3, 4, 5, 7 and 9 if digits may not be repeated? (ii) How many of the numbers so formed are even? (iii) How many of the numbers formed are divisible by 3? (iv) How many of the numbers formed are less than 700,000? (b) JACK MURPHY’s seven character password consists of four let- ters chosen from the ten letters in his name (all...
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?
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
How many distinctly different “words” can be formed using the letters of the word “OTTAWA”?