A database uses 20-character strings as record identifiers. Thevalid characters in these strings are upper-case letters in theEnglish alphabet and decimal digits. (Recall there are 26 lettersin the English alphabet and 10 decimal digits.) How many validrecord identifiers are possible if a valid record identifier mustmeet all of the following criteria:
Letter(s) from the set {A,E,I,O,U} occur in exactlythree positions of the string.
The last three characters in the string are distinctdecimal digits that do not appear elsewhere in the string.
The remaining characters of the string may be filled with any ofthe remaining letters or decimal digits.
