20. The application for a license plate states that the license plate number has 3 letters followed by a 3-digit number, for example, AEE123. The letters O and I and the digit 0 cannot be part of the license plate number. Any of the other letters and digits may be used up to 3 times. Which of the following expressions represents how many different license plate numbers are possible?

Answer and Explanation

Your Answer is

Correct Answer is H

Explanation

From the question, we can know that there are 24 choices for letters and 9 choices for numbers. According to the form given in the question: AEE123, and each number or letter can be used 3 times, so there are 24 possible positions for each of the three letters There are also 9 possibilities for the positions of the 3 numbers, so the result is 24×24×24×9×9×9