Question

In: Statistics and Probability

A certain website wants you to build a 6-character password from the letters a through i,...

A certain website wants you to build a 6-character password from the letters a through i, the numbers 0 − 9, or the symbols @, #, or &. Clearly, the order of the characters in the password matters

(a) How many passwords are there in total?

(b) How many passwords are there that consist of distinct characters?

(c) How many passwords have the first two characters be letters, the middle two character be one of the symbols and the last two characters be numbers where each character does not have to be distinct?

Solutions

Expert Solution


Related Solutions

An 8-character password consists of four numbers (from 1 to 9) followed by two letters (from...
An 8-character password consists of four numbers (from 1 to 9) followed by two letters (from A to Z) followed by two more numbers (from 1 to 9). a) How many different passwords can be formed if letters and numbers can be repeated? b) How many different passwords can be formed that have no repeated number or letters?
In an exactly 8 character long password where capital letters, small letters, and digits (0 to...
In an exactly 8 character long password where capital letters, small letters, and digits (0 to 9) must be used. Regardless of the order, how many passwords will use exactly 5 ones, 4 twos, and one Z?
A password is a sequence of five characters. Each character is one of twenty-six uppercase letters...
A password is a sequence of five characters. Each character is one of twenty-six uppercase letters (“A” through “Z”), one of ten digits (“0” through “9”), or one of five symbols (“+”, “-”, “!”, “<”, “>”). Count the number of possible passwords that can be created in each of the following scenarios. Consider each part of this questions separately. (a) There are no restrictions on how the characters are chosen. (b) A password must begin with a letter and end...
If you forget your password for a website and you click [Forgot my password], sometimes the...
If you forget your password for a website and you click [Forgot my password], sometimes the company sends you a new password by email but sometimes it sends you your old password by email. Compare these two cases in terms of vulnerability of the website owner.
An online account password for a certain website consists of eight characters, where at least one...
An online account password for a certain website consists of eight characters, where at least one must be a digit (i.e. a number from 0-9). a. How many different passwords are possible if only lowercase letters and digits can be used? b. How many different passwords are possible if a user wants to include single capital letter somewhere in their password? c. If a computer program randomly generates eight characters (such that each could be either a digit or any...
A 10-character password is to be selected from an alphabet comprised of the following: all lower...
A 10-character password is to be selected from an alphabet comprised of the following: all lower case and upper case English alphabet and all numbers. Compute the entropy of such a password. Why would such an entropy computation not be representative of passwords in practical settings?
The number of users of a certain website (in millions) from 2004 through 2011 follows. Year...
The number of users of a certain website (in millions) from 2004 through 2011 follows. Year Period Users (Millions) 2004 1 1 2005 2 6 2006 3 12 2007 4 57 2008 5 144 2009 6 361 2010 7 608 2011 8 846 Using Minitab or Excel, develop a quadratic trend equation that can be used to forecast users (in millions). (Round your numerical values to one decimal place.) Tt = Consider the following time series. Quarter Year 1 Year...
A marketing researcher wants to estimate the mean amount spent​ ($) on a certain retail website...
A marketing researcher wants to estimate the mean amount spent​ ($) on a certain retail website by members of the​ website's premium program. A random sample of 92 members of the​ website's premium program who recently made a purchase on the website yielded a mean of ​$1400 and a standard deviation of ​$200. Complete parts​ (a) and​ (b) below. A. Construct a 99​% confidence interval estimate for the mean spending for all shoppers who are members of the​ website's premium...
A marketing researcher wants to estimate the mean amount spent​ ($) on a certain retail website...
A marketing researcher wants to estimate the mean amount spent​ ($) on a certain retail website by members of the​ website's premium program. A random sample of 99 members of the​ website's premium program who recently made a purchase on the website yielded a mean of ​$1900 and a standard deviation of ​$200. Complete parts​ (a) and​ (b) below. a. Construct a 95​% confidence interval estimate for the mean spending for all shoppers who are members of the​ website's premium...
A marketing researcher wants to estimate the mean amount spent​ ($) on a certain retail website...
A marketing researcher wants to estimate the mean amount spent​ ($) on a certain retail website by members of the​ website's premium program. A random sample of 96 members of the​ website's premium program who recently made a purchase on the website yielded a mean of ​$1400 and a standard deviation of ​$200. Complete parts​ (a) Construct a 95​% confidence interval estimate for the mean spending for all shoppers who are members of the​ website's premium program. (Round to two...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT