Answer:
17,576,000
Explanation:
3 digits followed by 3 letters
Draw an underline character for each position with multiplication signs in between them.
_ × _ × _ × _ × _ × _
Now fill in each blank with the number of characters that can be used in that position. The first three blanks are used with digits, 0 through 9. There are 10 digits 0 through 9.
10 × 10 × 10 × _ × _ × _
For the last three blanks, each one gets a letter from A through Z. There are 26 letters to choose from fore each of the last three blanks.
10 × 10 × 10 × 26 × 26 × 26 = 17,576,000