Question 1
A company assigns employee numbers according to the following scheme:
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Each number must comprise three letters, followed by five numerals.
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The first numeral must be either '1' or '2'; there are no other restrictions on the numerals.
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There cannot be repetition among the three letters.
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To prevent confusion with the numerals '1' and '0', the letters 'I' and 'O' cannot appear.
Which of the following expressions is equal to the number of possible employee numbers?
Explanation: The first three characters must be distinct letters, none of which are 'I' or 'O', meaning that three letters will be selected from a set of 24. Also, order will be important, so the number of ways to choose this group of three will be 
.
The letters are followed by either a '1' or a '2', so this makes 2 possibilities.
The next three characters will be numerals, and there will be no restrictions, so the number of ways to choose this group will be 
.
By the multiplication principle, the number of ways to choose an employee number will be
.
The letters are followed by either a '1' or a '2', so this makes 2 possibilities.
The next three characters will be numerals, and there will be no restrictions, so the number of ways to choose this group will be .
By the multiplication principle, the number of ways to choose an employee number will be