Answer:
78,624,000 license plates
Step-by-step explanation:
For each of the 4 numbers, we have the following possibilities:
First number: 10 digits possible
Second number: 9 digits possible (one used)
Third number: 8 digits possible (two used)
Fourth number: 7 digits possible (three used)
For each of the 3 letters, we have the following possibilities:
First letter: 26 digits possible
Second letter: 25 digits possible (one used)
Third letter: 24 digits possible (two used)
The total number of license plates is the product of all these possibilities:
Number of plates = 10 * 9 * 8 * 7 * 26 * 25 * 24 = 78,624,000 license plates
