Re: A company ordered for security codes to be formed for each o
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04 Jan 2022, 11:45
Each code has 5 characters
Each code will have 3 of these characters as letters (X or Y) and 2 of these characters as Digits (1 or 2 or 3)
(1st) out of the 5 character order, choose which 3 spaces the Letters will take and which 2 spaces the Digits will take
For instance we can have:
Letter - letter - letter - digit - digit
Or
Lettter - letter - digit - letter - digit
Etc.
The number of different unique arrangements is given by: 5! / 3! 2! = 10
AND
(2nd) for each one of these 10 arrangements, we need to choose from the available options of Digits and Characters. Repeatition is allowed.
Digit 1 - 3 available options
Digit 2 - 3 available options
Letter 1 - 2 available options
Letter 2 - 2 available options
Letter 3 - 2 available options
Applying the Factor Foundation Rule, the number of unique codes that can be formed is:
(10) * (3 * 3 * 2 * 2 * 2) =
(10) (9) (8) = 720 possible codes