Answer:
1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20
20,442,240 account numbers are possible.
Step-by-step explanation:
The first character has 10 possible values.
The next 2 has 26 * 26 = 676 possible combinations.
The last 4 has 9*8*7*6 = 3024 possible combinations.
So the answer is 10 * 676 * 3024
= 20,442,240.
