Answer:
17576000 different possible license plates
Step-by-step explanation:
Note that in the question, repetition is allowed for both the letters and digits.
For the first letter, there are 26 choices to make. For the each of the letters, there are 26 choices for the second letter, and for each of the letters, there are another 26 choices for the third letter.
Therefore, this gives us 26x26x26 = 17576 possible pairs of letters.
For the three numbers, we have ten possibilities for the first digit, ten possibilities for the second digit, and ten possibilities for the third digit.
Therefore, this gives us 10x10x10 =1000 possible numbers.
The combined possibility of the license plates in both three letters and three numbers is 17576 x 1000 = 17576000 different possible license plates.