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Three digit codes 2019-07-14
From Jessica:
I need to find the total number of 3 digit codes using the digits 1 through 9. How many of these codes would be odd numbers, and how many even?
Answered by Penny Nom.
A three digit code 2019-07-14
From Hannah:
I have a briefcase with a three-digit code. I can set the code myself using digits 1 through 9, assuming that each digit can only be used once. How many possible codes are there?
Answered by Penny Nom.
4 digit codes 2019-02-27
From Sophia:
How many 4 digit codes can you get out of a numbered key pad ?
Answered by Penny Nom.
A four digit pass code 2018-02-26
From Jessica:
I was trying to fond out how many combinations could there be for a four digit pass code to a phone when no numbers are repeated?
Answered by Penny Nom.
The code on a new phone 2018-02-02
From Maria:
Hi -
My husband gave me a new Samsung Galaxy mobile for out anniversaire gift. He set me a challenge which I have to solve before I can use the Phone. He has set the pin code with numbers 4, 7 and 0 and created a four digit code with the said numbers. Is there a way I can somehow list all possible combinations and try them all? Thanks!

Answered by Penny Nom.
4 digit codes with repeating digits 2017-06-01
From Morgan:
what are all possible 4 digit code repeating numbers? cuz i know that you have one website on it but, it doesn't repeat 2 numbers in a code.
Answered by Harley.
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.
A six digit code 2016-05-06
From Ralph:
How many combinations are possible if a "safe" has four buttons and you can use a six digit code? (these are just single press buttons..)For example, this could be one possible combination: Button 4 Button 1 Button 1 Button 3 Button 2 Button 4. Thanks!
Answered by Penny Nom.
A five-digit pass code 2015-04-25
From Mary:

Question from Mary:

More on your published question:

I have the same type of lock, but set up a 5-digit pass code. Is that more or fewer possibilities than a 4-digit code. How many digits would make the lock most secure? I don't believe Werner specified this, but each number can only be used once. Thanks, Mary

Answered by Penny Nom.
A 4 digit code 2013-03-26
From chris:
I saw a previous question about a 4 digit code type thing and I was wondering if you could email me that same type of thing. I changed the pin number on my phone's lock screen and I tried hard to remember it, then I had to go help my mom with something and I automatically forgot it and there is no way for me to get back on my phone. I need all of the possible 4 digit number combinations without the numbers 0, 1, or 2. It cannot be repeating, ascending, or descending.
I know you may not want to do all of them, but I really need it.

Answered by Robert Dawson.
A valid UPC number 2012-12-22
From Jacob:
A valid UPC number , ABABABABAB- C must end in a 2 after using the rule:

3A +B+3A+B+3A+B+3A+B+3A+B+C=##2.

What would term C need to be in order to make the following UPC valid? 2741825293-C

Answered by Harley Weston.
A security code 2012-09-01
From Breanna:
The code is made up of five two digit numbers from 01 to 20 entered in a certain order. How many different security codes are possible with this system
Answered by Penny Nom.
A punch-code lock box 2010-11-29
From Doug:
I am a real estate agent that uses punch-code lock boxes on houses to store the keys. I need to crack the code on one of our boxes, so I need a list of the possible combinations.
4 digit code
Numbers 0-9
Each number can only be used once
Order of the numbers does not matter.

With advice from this site, I have calculated that there should be 210 possibilities. 10x9x8x7 (5040) gives me the total number possibilities and 4x3x2x1 (24) gives me the total number of ways to arrange those numbers. So if I divide the possibilities by the arrangement, I get 210. (5040 / 24 = 210) GREAT!!!

Now, how do I develop a list of those 210 combinations?

Thanks for your help.

Answered by Robert Dawson.
My phone is "sim locked" 2010-06-10
From Daniel:
Question from daniel:

got a phone that says sim locked, it requires 0-9 digit code to get in, how many combinations could there be if you could please list the possibilities, the number can be repeated.

Answered by Penny Nom.
A three digit entry code 2010-04-14
From Bryon:
The entry code for the executive bathroom is a three-digit odd number with no repeated digits. If you want to try to break in, what is the maximum number of numbers you'll have to try? (Remember that the three-digit numbers cannot start with zero.)
Answered by Stephen La Rocque and Penny Nom.
A code on my pedometer 2010-02-19
From Jacqui:
Hi I need to break a code on my pedometer. I have only 3 digits 1 2 and 3 but need to fill a 5 digit code. I have tried to find answers but they seem to relate to if the digits are only used once. I can use them in any order and repeated as many times. How many possibilities are there and is there an easy way to run through them. Many thanks
Answered by Tyler Wood.
A 4-digit phone code 2010-01-21
From pat:
my daughter can`t remember her 4-digit code to unlock her phone. she is pretty sure it starts with a 4. can you help us? my brain is locked up
Answered by Robert Dawson.
A four digit passcode 2009-01-12
From john:
i have a machine at home that has a four digit passcode and the numbers range from 1 to 4 how can i get all the ways those numbers can be used
Answered by Harley Weston.
Zip codes, postal codes and 5 digit codes 2008-07-08
From Mike:
Sorry if you have answered this before but I don't understand the explanations I have seen. How many possible combinations are in a 5 digit code (like a Zip Code). Is there an equation that can be used for this type of question?
Answered by Penny Nom.
Break this code 2008-04-16
From Kim:
The most common letter used in the English Language is E. The next is T. Vowels O,A and I are the next most common;then comes the letter N.

Use this information to break this code.


Answered by Claude Tardif.
A 4 digit passcode 2008-02-16
From Rob:
If there is a 4 digit passcode with only 6 punch in symbols, how many possibilities are there and what are they? symbols are: Y, X, RB, RT, LB, LT. Please get back to me, thanks for your time and help.
Answered by Stephen La Rocque.
Zip codes 2007-12-03
From Natalie:
How many 5 digits zip codes are possible if digits can be repeated?
Answered by Penny Nom.
How many three button codes are possible? 2007-08-23
From kim:
A home security device has ten buttons and is disarmed by pushing three buttons in sequence. How many three button codes are possible if each button can be pushed more than once in the code?
Answered by Stephen la Rocque.
I need all the possible 4 digit combinations... 2007-07-18
From Jo:
I have lost the code for my car stereo. I need all the possible 4 digit combinations using the numerals 1 2 3 4 5 and 6. Thank you
Answered by Penny Nom.
Five button push lock 2007-07-06
From Jeffrey:
We have a 5 button push lock and we were wondering how many different codes were possible in this situation. In this lock each button can only be pressed once (ie it's not a numbered key pad) and order matters. How would we find out the # of possible codes?
Answered by Stephen La Rocque.
A 4-digit access code 2005-01-02
From Missi:
I need to find the 4 digit number to access my voice mail. These numbers will be 0-9 & numbers can be repeated. Could you provide me with a list of possibly combinations? If not, do you know anywhere that I could get a list of combinations so I don't have to write it all down?
Answered by Harley Weston.
A zip code problem 2000-10-26
From Rob Mathis:
Find the zip code of a place in a county so that the product of it and the zip code of another place in another county of the same name, but in a different state, is an exact multiple of the number 123456789
Answered by Claude Tardif.



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