A database uses 20-character strings as record identifiers. The valid characters in these strings are upper-case...

A database uses 20-character strings as record identifiers. The valid characters in these strings are upper-case letters in the English alphabet and decimal digits. (Recall there are 26 letters in the English alphabet and 10 decimal digits.) How many valid record identifiers are possible if a valid record identifier must meet all of the following criteria:

Letter(s) from the set {A,E,I,O,U} occur in exactly three positions of the string.
The last three characters in the string are distinct decimal digits that do not appear elsewhere in the string.
The remaining characters of the string may be filled with any of the remaining letters or decimal digits.

Expert Solution

Colby Messinger answered 2 years ago

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