Math Central - mathcentral.uregina.ca
Quandaries & Queries
Q & Q
. .
topic card  



list of
. .
start over

6 items are filed under this topic.
A 4 digit combination lock 2019-02-02
From Brijanshu:
I have a lock that contain only four no. 6,7,8 & 9 . How many possible password of four digit containing these Number.
Answered by Penny Nom.
A lost iPhone pass code 2017-04-17
From Sam:
I have a locked iPhone and it has all my of my holiday photos on it. I changed the password and then I think I did a incorrect number pattern but anyway I know it ends with 99 and the first 4 digits are 235 and 6 could you please send all of the combinations for this password (without the 99) Thx and plz get back ASAP I need it for school
Answered by Penny Nom.
Six-digit passwords 2013-03-19
From Judy:
Can you please explain why the answer to the following question is 10^6? What is the number of possible six-digit passwords when using the digits 0 through 9, with repetition allowed.
Thank you.

Answered by Penny Nom.
Passwords 2009-07-08
From Tim:
pretend I have a password that is - 9k7d4112p5o

assuming that you continuously guessed wrong until that exact combination was the only possible answer left; how many times would you have to guess?

capital letters are not relevant and you do not know how many digits there are

Answered by Stephen La Rocque.
2 password policies 2007-10-17
From Larry:
2 password policies are in question.
Policy 1 states that a password must be between 6 and 8 characters
Policy 2 states that that a password must be exactly 8 characters.
Both policies state that Passwords can contain A-Z a-z 0-9 (26*2)+ 10 characters to choose from.
Which policy is stronger?
How many potential passwords exist for policy 1 and how many for policy 2?

Answered by Penny Nom.
Nine character passwords 2007-03-27
From oliver:
suppose a password consisted of a string of nine characters from the english alphabet(26 characters). if each possible password could be tested in a microsecond,how long would it take to test all possible passwords?
Answered by Penny Nom.



Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.



Home Resource Room Home Resource Room Quandaries and Queries Mathematics with a Human Face About Math Central Problem of the Month Math Beyond School Outreach Activities Teacher's Bulletin Board Canadian Mathematical Society University of Regina PIMS