How many combinations can be created with 2 letters, 2 numbers, and 2 letters?

In summary, the conversation revolves around creating a random combination (code) for a client using 2 letters, 2 numbers, and 2 letters. The total number of combinations possible is calculated to be 21,233,664 by multiplying the number of choices for each character. The issue of duplicates is raised, and the idea of de-duping or removing duplicates is mentioned. The conversation also touches on the concept of true randomness and the process of generating random numbers.
  • #1
reldridge
5
0
I am creating a random combination(code) for a client. I need to see what the total number of combinations there can be.

Please let me know if I am using the wrong word Combination vs Permutations.

Formula:
2 letters + 2 numbers + 2 letters
example: TR12FR

The random letters are taken from 24 values:
ABCDEFGHJKLMNPQRSTUVWXYZ

The random Numbers are taken from 8 Values:
23456789

Any help would be greatly appreciated.

Thanks
Ryan.
 
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  • #2


combination is right you're selecting letters, numbers and more letters:

Choices for each character of your 6 charcter code:

24 * 24 * 8 * 8 * 24 * 24 = total number of codes possible

Now if these could be rearranged then you'd have to worry about permutations to elimnate repeats in your counts.
 
  • #3


Thank you -

So de-duping these down to create 2.5 million unique codes using this formula will not be an issue, sense there are 21,233,664 possibilities.
 
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  • #5


Well sense this is just a random generator out of excel the possibility of it creating a duplicate is there, so i will need to just remove dupes, or nth select down to 2.5 million unique codes.

Just needed to make sure that the 6 digit using that formula could create that many unique codes.
 
  • #6


reldridge said:
Well sense this is just a random generator out of excel the possibility of it creating a duplicate is there ...

So you have a belief that "true" random would not include any dupes?

How would you create 100000 consecutive random numbers from 1 to 100 ?
 
  • #7


this reminds of how new programmers used to construct a deck of randomly sorted cards.

generate a number from 0-51 check if its present in the crd deck array if so then generate another.

The better approach is to generate a sorted sequence of cards into an array and then to randomly shuffle two cards by selecting two indexes at random and swapping the cards.
 
  • #8


phinds said:
So you have a belief that "true" random would not include any dupes?

No belief, was just stating that there could be duplicate codes during the random selection and i would need to remove the duplicates until reaching my goal of 2.5 unique codes...
 
  • #9


Thanks for the help.
 

FAQ: How many combinations can be created with 2 letters, 2 numbers, and 2 letters?

What is a random combination?

A random combination is a set of elements or variables that are chosen without any specific pattern or order. These elements are selected randomly, which means there is no predictable sequence or arrangement.

Why is creating a random combination important in science?

Creating a random combination is important in science because it helps eliminate bias and ensures that the results of an experiment are not influenced by any predetermined factors. This allows for more accurate and reliable data analysis.

How can a random combination be created?

A random combination can be created using various methods, such as using a random number generator, drawing names or objects from a hat, or using a computer program. The key is to ensure that the selection process is truly random and not influenced by any external factors.

What are the advantages of using a random combination in scientific experiments?

Using a random combination in scientific experiments helps to ensure that the sample is representative of the population being studied. This reduces the likelihood of getting biased results and allows for more generalizable conclusions to be drawn from the data.

Are there any limitations to using random combinations in science?

While using random combinations can help eliminate bias, it does not guarantee that the results will be completely unbiased. There is always a possibility that chance or other variables may affect the outcome of an experiment. Additionally, random combinations may not be feasible or practical in certain situations, such as when studying a small population or when resources are limited.

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